Maybe my answer fell short by not suggesting, as an example to apply in the thought experiment, the tidal forces of the moon upon the earth. The fact that the gradient in this case is due to the target spinning, and not the source, is immaterial. The point to bring away is that gravitational gradients are associated with real work, and that thermodynamics apply as they do to other phenomena in the same reference frame. In the relativistic regimes that apply within and around ultra-dense matter, there is little that is familiar or that behaves familiarly, so even when it's well understood, those of us who can't fathom the math required to describe it are going to have to accept that "we don't get it" without qualifying it with "therefore I doubt it".
Before I am willing to consider a theory useful, I require that it be consistent with observation. It's one of my quirky personality traits that annoy a lot of people who prefer to treat science like a religion and take things on faith. I'm much more concerned that they agree with observation than I am concerned about their mathematical self-consistency or there lack thereof; or their elegance or lack thereof. I want a theory to first describe accurately what we have already observed, and then to make testable predictions that lead to further observation that then agrees with those predictions.
Let's look even at some very mundane things; thermodynamics for example, the idea of entropy; really is only valid in a closed system. Of coarse if you believe the big bang, the universe as a whole is a closed system, I don't, but for the sake of argument, let's assume that it is. The universe that we see around us is quite ordered, the orbits of planets have an orderly relationship in terms of their distance from their parent star for example. The stars have predictable orbits within their galaxies. There is a visible structure to the way the galaxies are positioned in space, not just randomly strewn about. Life, is an extremely complex but ordered system.
Where did all that order come from? Big bangers would say the universe was wound up by the big bang and has been winding down ever since, but arguably there is far more information and order in the universe today than there was hypothetical seconds after the hypothetical big bang. Now if we don't have a closed universe, and I don't believe that we do, then this ceases to be a problem.
Big bang theory says that the first galaxies were small and irregular, and the larger spiral galaxies familiar today resulted from the accretion of smaller galaxies. When I saw the first deep field Hubble photographs, I was almost convinced. As illogical as everything relating to big-bang theory seemed, the visual evidence seemed to be overwhelming. But then I had a flash of insight. Hubble you see, can only see in the optical and near infrared, it can not see in the far infrared or the millimeter wavelengths where the optical emissions of very high red-shift galaxies have been shifted to by the time that light reaches us. Thus when Hubble is looking at very distant high red-shift galaxies, it's looking at the extreme UV regions of those galaxies only, the regions with dense new star formation. So naturally, those galaxies appear small and irregular.
Images from UV and X-ray telescopes of local galaxies convinced me of this because they appeared just like those in the Hubble deep field images. Then Spitzer took pictures of the distant galaxies in the deep infrared, and lo and behold there were large spiral galaxies and in general a mix looking very much like what we see locally. There were in fact spirals discovered that were estimated to be less than a billion years from the big bang that were larger than the Milky Way which is a sizable galaxy as galaxies go. It was estimated that at least one of these large spirals had a rotational period of several billion years. It had achieved remarkable symmetry for something that had only been around for one third of a rotation. If galaxies had already grown to the size of the Milky Way and beyond in the first billion years of galactic evolution, then we ought to have bunches of super huge galaxies 12 billion years later; but we don't, we have essentially the same mix.
Then there is the metals conundrum. Big bang theory assumes the universe was primarily hydrogen, a lesser amount of helium, and just a tiny amount of lithium, and that was it; all heavier elements forged in supernova over the eons. Early measurements seemed to confirm this; distant galaxies, to the degree which spectroscopic data could be obtained, seemed to indicate a metal poor population of stars; just what the big bang model would predict. But then later I came to understand that these early measurements were comparing apples to oranges, they were not comparing the same regions of the galaxies and there is very large differences in metallicies between the central bulge of a spiral galaxy and the galactic arms; so the differences were due not to age, but to the different parts of the galaxies compared. When like regions are compared, the metallicy, most of this variability in metallicy disappears.
Quasars; we don't see many of them in local galaxies; so must be an indicator of galactic evolution right? What an interesting indicator they are, because while they are assumed to be the active center of early galaxies, their redshift in many cases is different than that of their host galaxies, sometimes considerably different. Statistical analysis showed that it wasn't just a chance alignments of galaxies and quasars creating the appearance of quasars with different redshifts than their host galaxies, there were far too many.
This one's still open to debate, but redshift itself appears to be quantized, then a supposedly more accurate survey found that no, it wasn't; then another survey that followed up on that one found redshift to be quantized, so I don't know, jury still out on that one as far as I am concerned; but if true either there has to be a mechanism besides Doppler shift responsible for a portion of the redshift; and I believe that to be the case, or the velocities at which other galaxies are receding are quantized.
These are just a few examples of things about existing theories, particular with respect to the big bang, that I find problematic. To be honest though, sometimes I think the Hindu's have it right and we're just making it all up as we go along anyway.