Camera manufacturers, more than anyone else, does have the best "know-how" on where to place, what.
Every single control or surface on the camera, just like its feature set, has been carefully studied and modified, over the years, to assure giving its user the best experience with the product, taking into consideration other factors, such as logical layout, ease of use, underlying circuitry / electrical connections design, control or surface design costs, and the like.
I am sure that the standard, factory camera strap mounting points, pretty much in the same places as where they could be found, as far as I came to know cameras, many, many years ago, are still 'there' for the simple reason that the manufacturers deem it best that the camera be carried around in the "upright" position.
It may also be because those areas to the sides of the camera's top cover, wherein the camera strap lugs are located, are securely attached to the camera's chassis, thereby providing for the best attachment point for the camera's strap.
I have yet to hear of a malfunction or failure of the factory camera strap attachment point, in normal use, professionally or otherwise.
I am not saying that carrying or attaching the camera straps by an alternative method, using the tripod mounting hole at the bottom of the camera, is not at all good. What I am saying is that the tripod hole was not designed nor intended by the manufacturer to be used as a point for camera strap attachment. I guess that everyone knows that - hence the part name - tripod mounting hole. It is, logically, intended for use in attaching the camera to a tripod.
I think that no one has ever made, to date, of a comprehensive enough study (or extensive research) on the possible effects of using the tripod mounting hole for camera strap attachment, nor of the possible detrimental effects of carrying a camera (dSLR) upside down.
At the moment, it seems like it's purely a matter of personal preference, if one intends to use aftermarket parts or accessories that would enable the attachment of the camera straps, elsewhere, than where the manufacturer intended.
I have a friend, who, using a tripod hole mounted Quick Release System, had his dSLR dropped to the floor, lens first, due to a swivel pivot point failure, the same being worn out, that it broke-free from the part that slides along the camera's strap.
The matter could have been avoided from ever happening, if not for that aftermarket "accessory" that he had mistakenly 'fallen for.'