It's actually kind of funny to read all these posts from people offering "different" perspectives and failing to see that; at the root of it, you're all saying the same thing.
1) Bioware put out a promotion that is perceived to alienate a number of it's paying customer base.
2) Subtext with the promo is that they recognized once a player hit the level cap they really had nothing to do other than dailies and FPs (if you could find a group), so this free time was to keep those players around so that they would be here if they could manage to get the content to satisfy them out soon.
3)Due to #2 you've created a perception that other paying customers who have many many toons (i have 15 spread across different servers myself), but not a single 50 yet are less valueable, and this takes us back to the first point.
it's not about the $15, it's about the perception of what was said and the principle behind that message.
The one simple solution to this was - if you had an active subscription on xxx date, you get 30 free days as a show of gratitude for your business. Done.
Sure you'd get people complaining that, hey I've been here since launch so I should get more, but those arguments would hold a lot less weight than those posting here.
From a PR perspective they've dropped the ball a bit here and added to their notorious reputation (EA that is) of being arrogant and uncaring of their customer base.