Except that allotments of divine and arcane power have always been rationalized. The explanations have not always held up to scrutiny, but they were there. No previous edition has ever tried to explain how the fighter can only make 'five attacks per two rounds' once a day, because that would have been silly. Fighter abilities have always been 'at will', which is why they were relatively weaker than divine or arcane powers. Sure, the MU may have fireball memorized three times, but the fighter can swing a sword all day long. Because that matches with people's perceptions. Granted, four or five combats a day would have even the most well-trained fighter exhausted, but there is already a mechanic for that without limiting whatever tricks they can pull off.
What doesn't match perceptions is teamwork that only works on a diurnal cycle. What doesn't match perceptions is a bleeding ability that not only works against hit points that don't represent physical damage, but also only works once a day. Especially after shutting down the console having played X-Men Legends or Ulitmate Alliance, where Wolverine or several other characters get bleed damage on every attack. What doesn't match perceptions are mundane (non-magical) abilities that have a magic-like limit on their uses.
For example, the martial characters we have seen show 'melee attack' as an at-will. Can I swap that with a per-encounter? Does everyone get 'melee attack' on the at-will list, but martial characters get it free? Does the Wizard not get a 'melee attack' if they don't take it as one of their at-will powers? Or is it a per-encounter for the Wizard?
I believe Martial Powers is going to remain a large stumbling block for some time to come.