The thing is, for me, I got bored of vanilla minecraft a good while ago. It feels like I've done most of the stuff.
Sure, I COULD build a giant castle out of ice, but it's just applying the same stuff I've learned before over and over and over...
That's kind of the point of playing multiplayer, though. Having people to interact with. Logging on to see a new megaproject sprout up. Seeing other people's designs. Community. Working together to make things happen. Competitions. Games. Participating in a world that evolves. Logging on on easter to see that somebody made an egghunt. Or that somebody put red woolen blocks across the world with cryptic messages on them.
Simply adding mods doesn't give any of those things. It mostly gives new blocks and mobs and cosmetics and things. If that's all you want, you may as well pick and chose the ones you want and play solo rather than trying to coordinates a server that has the mods you want but not the mods you don't want then deal with getting everyone else to install all the same mods, and then be happy with the added block lag.
Nothing against mods, but to me it's not the point of SMP.
If anyone's got a stack mossy cobble they'd be willing to lend, I could resume contruction.
I doubt I have a full stack, but I'll check. If i recall correctly there's a zombie spawner dungeon somewhere beneath the town at (-300,500) that as of last I saw nobody had bothered to turn into an xp farm. Probably still some there.
EDIT:
I can give you a stack of mossy stone brick. Will that do?