I'll agree, ToA was the reason I took a few months off. I was completely turned off by the fact that getting a regular PvE group was hard enough, and ToA requires that you have mega Battle Groups that are 3-5 regular groups in size.
However NF has put the focus back on RvR. None of my toons have any Master Levels from ToA, yet they are still able to compete in RvR, and quite effectively too. The ToA master level benefits are really just minor nice-to-haves, they aren't so overpowering that they tip the tide of battle in favor of the haves vs. the have-nots.