I think the fundamental problem is that people don't do the analysis based on what kind of floor construction they are dealing with and what kind of problems are present. For example, my listening room has a solid concrete floor sat on top of clay subsoil, and the house is sufficiently far from the nearest road (~100 metres) that subsonic vibration from traffic just isn't an issue and wouldn't be even if it was a suspended floor. So I don't need to isolate the (floor mounted) speakers from the floor - there are no external vibrations to cause a problem, and the speakers aren't going to make the floor resonate - what I need is strong coupling, so the speakers don't rock, which in practice is just a matter of standing them on adjustable feet - gravity does the coupling job perfectly well.
In contrast, in my previous house, we had Victorian wooden suspended floors which flexed considerably, and some kind of isolation would have helped to reduce the degree to which the speakers excited resonances in the timberwork. However, not all suspended floors have that issue - my study/workshop where I run a second system (also floor mounted speakers) is a timber suspended floor, but the floor construction is much more massive than normal, partly because it has a double layer of floorboarding topped by porcelain floor tiles, and it is pretty inert vibration-wise. Having the speakers directly coupled to the floor (adjustable feet again) works very well indeed.
Horses for courses - but it always helps to be able to distinguish between a horse and a donkey, and to tell the difference between a racecourse and a dog track (to mix several metaphors).
