This debate emphasizes the split between MMO's as games versus MMO's as worlds. As a game, the correct answer to the question "can I play with my friends?" is always yes. By contrast, the very structure of the persistent online world is full of "no" answers to that question.
- Wrong server/faction? No.
- Wrong class? No.
- Wrong spec/group role? No.
- Wrong level? No.
- Not enough gear? No.
- Don't own enough expansions? No.
- Not located in the right location (back in the days when traveling across the world could take all night)? No.
A solution worth trying?
In the short term, I think there are legitimate questions about whether this approach will work or is a good idea. As Azuriel points out, some of these goodies represent money left on the table for Blizzard, and it's not clear how many of the returning players Blizzard will be able to retain. That said, I think it was overdue for someone to try this, and Blizzard is one of the best positioned, even after the rough year.
As long as entire segments of the game - such as solo content, non-raid group content, etc - are reduced to a prerequisite that raiders must complete to be allowed to advance, there will be consequences to the way that players who actually want to use this content are able to experience it. In Cataclysm, Blizzard expended a staggering amount of resources on new leveling content that even their core demographic for this material - longtime players like myself with high nostalgia value and willingness to roll alts - can't use the content because the rush to level cap ruined the exp curve for everyone else.
As damaging as paying to skip to max level (the next logical step in this progression) may be to the MMO's, I think the consequences of continued inaction may be worse.