I think guys secretly like the drama. Maybe it makes them feel alive or brings some action to their otherwise dull lives. Or, perhaps it reminds them of the chaos of their own family life as a child ... Or, they could just be weak guys who like being dominated and repressed.
Lauren Fritsky, in response suggests possibly, "men need to feel needed" and and are with such crazy women to boost self-esteem.
Ami Angelowicz, to one up them all, adds five possible theories (ht Glenn Reynolds)
1. Men love to be heroes. They love to “fix” things. It makes them feel needed, important, and feeds the male ego. Who makes a better damsel in distress than a poor, defenseless lunachic? Note to guys: a woman is not like a house. Fixer-uppers do not usually turn out to be a wise investment. If you need to fix something, there are plenty of us normal single girls out there who need some light bulbs changed.
2. If she’s crazy day to day, chances are she’s crazy in the sack. But men don’t really care about sex that much, do they? Wait … I think they might.
3. He has mommy issues. If a guy had a dysfunctional mother (or primary family member) he may not actually be aware that his lady’s behavior is NOT normal. There’s no shame in going to therapy and working that stuff out.
4. Need to figure out your future career? Money troubles? Feeling anxious or depressed? Having a GF with problems much worse than your own is a wonderful distraction. Warning: she will only make your problems worse.
5. He is not ready for a real intimate and committed relationship, and we all pick the wrong kind of person when we’re not ready. As soon as he envisions a lifetime of cracked-out antics, chances are he’ll be on the road to Mrs. Rightville, ASAP
As a guy who has in the past been attracted to some crazy chicks I think I'm in a position to provide insight. From my perspective, I think Shallon Lester gets closest to the truth.
First, I should say, that this is not something confined to just guys. People in general are attracted to "crazy" people, in the sense that we're talking about here (see the movie Withnail & I for a perfect example of a crazy guy like this). The key to this type craziness is a lack of inhibitions which is what leads to the mood swings, the unpredictable actions, and the inability to really make long term commitments. Such people are attractive because they're more interesting, more exciting, more unpredictable. People who deviate from expectations are just plain more interesting and we're attracted to them.
Many people are scared by such unpredictable people, but others are simultaneously attracted to them. The men who are attracted to these crazy chicks (like me when I was younger) are definitely not going to be more dominant personalities ("more spineless," one might say) and are also probably going to be more open to novel experiences. And, I sort of agree with Angelowicz on number 5: if a guy starts thinking long term with a crazy girlfriend he's going to have to think either that he can somehow tame her, without losing the excitement of her crazyiness (unlikely, but a guy can still dream right?) or he's going to drop her for someone more stable.