If you were Slowpoke101, what would matter more to you? Keeping your word to your good friend Eloraam, or releasing an update to appease the unnamed faceless?
Both. Apeasing the masses means a better name and reaching more people. More people means more people that give donations. More donations results into more options for a modpack team. And here is the thing, you can still do this while keeping a good relation with your friends. Its pretty much a win win provided they have the time to do it.
So unlike a bug report, It is useless feedback from a beta tester to proclaim they want an updated beta.
Unless the bugs are fixed into updated mod versions, wich by themselves might causes new bugs due to added content. Wich cannot be tested! Additionally they might have made changes to ore generation, recepy's and/or things like what goes into wich bag from forestry, have all ore be able to go into each furnace etc. That is all feedback given wich we dont know if it was implemented/fixed or not. Upgrading to another beta version would give players a better understanding of where FTB is going and help shape of the final edges.