RP2 didn't "just give up for a while," based on what I've read. 1.3 was an update of truly gigantic scope, and broke pretty much everything, including almost everything about RP2. It broke so bad that, if I remember correctly, Eloraam had to, more or less, create RP2 from scratch come 1.3. A mod that huge is going to take a pretty long time to recreate. Hell, look at EE3: its been around since, what...1.4.7? Its still not done because the plans for it are huge and Pahimar, like every other mod maker out there worth a shit, has a life to tend to.
Honestly, I'm all for skipping updates. I'm seriously considering skipping 1.7 for mine because, quite frankly, Mojang is releasing too damned many updates too damned fast for my tastes. It feels like they barely give any time for the updates to get so much as a few serious bugfixes before they're working on "the next big thing." They're too obsessed with adding more and more shit, instead of making the shit they have work better. The new 1.7 biomes look really nice, I'll grant ya that, but getting rid of static item IDs? Honestly, that's something they should've done during 1.0 or even before then because the system in use now is, to put it bluntly, stupid and inflexible. Then again, they probably didn't expect the game to garner as many mods as it has; I've not seen a game with nearly as many mods as Minecraft's gotten in the past year or two.
I've found vanilla to be dull for a while now. The new stuff in 1.5/1.6 was nice for about a week or two, but I grew tired of it pretty easily because it was all kinda shallow. The mods add a great deal of necessary depth to Minecraft, for me. The only reason I enjoy playing vanilla with my girlfriend is that I've got her along for the ride; otherwise, I'd be bored within an hour and would move on to something else that's more engaging.