There is probably some curve you can draw where the cost of accurately reproducing bass notes increases geometrically with lower frequency, requiring increasing quantities of power, woofer area and box volume and bracing.
Yes, exactly.
As for decent bass from most modern speaker designs - I'd agree with that too.
I took the term "palpable, appropriate" to be the OP's criticism of most small box big bass sound. I think it is fair to say that with small speakers either
1) You can have very limited bass extension but excellent bass.
2) You can have great bass extension but merely "good" sounding bass.
You can't have 1) and 2) at least not at realistic SPL levels - so you can't have your cake and eat it so to speak.
The points made about room eq wizard are also important - as the room/setup can spoil the bass through suckouts and humps.
