If you want stable payments, use a big pool, if you want some excitement, use a small pool. If a system was put in place to smooth out the payments and eliminate "casino", why not just move to a big pool?
Funny how you are asking for stable payments while just a few weeks back Philip was insisting the solution was to offer solo mining where things are pretty much all-or-nothing super-casino.
Because people want Bitminter to grow. So having 2 tiers ( 'casino' or 'safer' ) may see the big boys come over here ( and away from GHash ). A bit of customer choice, rather than the rather unfriendly 'like it or leave' too many roll with.