SL live music relies on groups. Yes, a lot of musicians have subscribos, but you know what, I hate having to be on a subscribo when I don't have space for the group because firstly I can't participate in group chat and secondly, when the notices for an imminent gig go out, the subscribo messages are too easy to miss. I want and need to be in more groups, not fewer!
Is the reduction in groups going to persuade me to become a premium member? No, absolutely not. Will the reduction in groups be yet another SL irritation that drives me to spend less time and money here? Yes, absolutely.
If there was some sort of half-way house between free membership and premium membership, of a couple of USD a month (max 3USD), then I'd consider it if it provided me with 100 group slots.