I used to bash spandex too. Until I started doing 100 to 200km road rides on my bike. The difference in drag/wind force is night and day. Now I shake my in spandex all over Simcoe county, and I'm dam proud of it.
Guys don't do it to look tough, obviously, that's a ridiculous statement (made earlier in this thread).. It's 100% for function, and not looks.
And for the drivers that think all cyclists wearing spandex are fags, and wimps. Be careful with that. You never know who your messing with. Take my spandex clad wimpy looking cyclist for example. I've been a self defense instructor for 15 years. Training hard in the martial arts my entire life. I'll never yell at a driver, or cause a fight, despite nearly being killed several time by ignorant drivers. But if you get in my face over sharing (or not sharing the road like in most cases with ignorant drivers), i guarantee it will not go good for you.