*the following is not based on any numbers or hard facts... just guessing

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I think this would confuse the user base too much. Nowadays, with the many different rpg systems around people at first decide what game philosophy suits them best and then they will play that game. Now over the years that system will get a steady, if not growing, customer base due to how the game mechanics work compared to other systems (or it will go under if its too bad, too exotic or too complicated). If people do not like the rules after a few tries they will switch to other systems, otherwise they will stick with it, even over many years. Now imagine having such a drastic (ok, "drastic" is a wee bit over the top term, but let's use it for now) change as you propose for the next edition of 4e. I do not think that would work out well with the existing user base cause they are used to a certain way of how the game works. And changes like that would alter those mechanics too much so in the end you would probably see more people leaving the system than you would be able to gain because of those rule changes. It is my impression that the gold fields of RPG are more or less claimed and fortified nowadays. There are not too many more "virgin" gamers out there that could be lured into a new system so todays companies have to try the impossible mix of a) adding new stuff to justify new editions and b) keeping those changes in a range where they wont loose existing customers.
I think your proposal for 4e being point and level based would go too far. There are other systems out there that have the same or similar mechanics so why should D&D be changed in that direction.
*end of pure speculation and guesstimation*