Its about wanting to play. How bad do you want to do it? (i'm noy speaking to anyone specifically here, btw) If its not that important to you, you'll find plenty of excuses to ditch the game, weekly, bi-weekly, or monthly. I've known plenty of people who have jobs, families, AND long commutes to get to a game...but they make it to the game. Because it was important for them. Its their favorite hobby. Most anyone can scrape together 4 or 5 hours to play a game if they wanted to actually play the game. Especially if ita s regular game that they known to plan for. Anyone can come up with a an excuse to ditch and i've seen someone use being married or having children as BS excuse before, more than once. Ocassionally, things happen (sick child, work schedule) and you miss a game. It happens to everybody. But if it happens a lot, odds are its more that you don't care that much about being there than you having a fuller life than other people. Own up to it. Its the rare, RARE bird who's life is so chaotic or "full" that they can't put aside 3-5 hours a week/month to do something they supposedly like to do.
My pet peeve is those "gamers" who know they aren't THAT interested in making a weekly game, but will commit to the game. Then they miss regularly and feed you a bunch of lines. Its much better to say "Hmmm...naw, i don't think so, man. I can't make it" than to say" A game? Hmm...every week? hm.....uh...yeah, okay, why the hell not?" I don't want to make it sound like joining a game group is like like joining the mob, but don't commit if you're not into the life!
I'll also chime in with some of what the others said. If your SO isnt a gamer, that can be trouble. But even then, i can't see a reasonable SO (or maybe i've just been lucky) getting that bent out of shape if you spent a night out with your buddies once a week. Its okay if your SO thinks gaming is a waste of THEIR time, but when they think its a waste of YOUR time, you've got a problem.
Also, like Cmanos said, the more players you have, the more disruption you'll encounter. I prefer 2-3 players. I'll go for as many as 4 or 5, if they are all on the same page (rarely happens). But beyond that i'm not likely to stick around. I like cohesive story lines and character backgrounds. With a small group, things are much easier to keep tight and trim. With each extra player you add above 3 or 4, you add a disproportionate amount of chaos, incompatibility (both schedule and personality wise), and white noise to the game.