MFC will always be slow for some, busy for others. I find it far more helpful to stop thinking about whether the site is slow or not, and focus on what I can do to keep it busy. Otherwise you're left with excuse after excuse for why "MFC is slow" which eventually takes all of the power out of your hands and turns into a vicious cycle. Summer: guys are vacationing with their families. Fall: back to school, football season. Winter: Christmas, New Years, etc. Spring: moar sports? There's always going to be a big event going on, a new videogame out, families to attend to, and just life in general.
It's self-defeating to dwell on it, I think. There are tons of guys on MFC looking for something that someone isn't offering at any given time.