Sadly, i don't think this has anything to do with sc ii sucking or not. I noticed most ToJ people constantly drift from game to game to game every time something new comes out.
I don't know if it's so much "drifting" as "approaching equilibrium."
When a new and highly anticipated game is released, gamers tend to temporarily spend most of their gaming time on that one game. As time goes on, they start picking back up other games they played.
My situation is unique in that I regularly play 4 different games (UT3, TF2, L4D2, and SC2) on set days. When SC2 first came out, I squeezed in a few more SC2 matches (and campaign missions) here and there as time allowed. Now that the game's been out a few months, I still play on Straturdays (when others show up on TeamSpeak, that is), but usually not at other times.
I also recently received a Playstation 3 and two games as a gift, so I've been spending more time in the living room again.
I also have a rather lengthy backlog of games on multiple systems to get through.
And whatever game my wife wants to play with me, of course, trumps all other games.
In short: Yes, SC2 is an awesome game, but (in my estimation) most gamers are dividing their gaming time (which is limited to begin with) between multiple excellent games. That's why game night/day events are so helpful to many of us.
Really it seems like very few ToJ members stick hardcore to one or two game titles. I can promise you i'll always be here until the next instalment of starcraft comes out. Same with Unreal Tournament. I don't plan on ever leaving sc or ut series for something else because i don't see anything better than those two games.
I've been playing TF2 regularly for a few years now. I'll play L4D2 with ToJ members on Wednesday nights as long as my schedule allows and there's at least enough interest to regularly fill a campaign lobby. I plan on playing SC2 for years to come as well. I'll probably still drop by Unreal Mondays as long as activity holds, but if I have to curb my gaming time in a given week, UT3 will likely be the first game I'll give up. (Nothing personal; I just like TF2, L4D2, and SC2 better.)
Of course, my gaming schedule is nice and organized right now. I wonder if that will hold once
my and Ember's little one arrives next February.
Althought I will agree the single player was painfully short. I think this was due to the ammount of work put into the cut scenes. 
