Well, this will obviously depend on many different factors, namely your edge over the opposition and given how cash game format allows for a fairly big edge to be had, it's of course theoretically possible to be a winning micro stakes grinder on stars. However, the truth is that PokerStars was never a good place for micro stakes players, even before the rake and VIP program changes. The rakeback on stars for NL2-25 players was always very low and if you're serious about grinding those stakes you're better of looking somewhere else. If you're looking for a bigger room with a good software PartyPoker is probably the best alternative followed closely by various Microgaming skins.