I'm definitely a homebrewing evangelist, but I've backed off a little bit on converting some of my friends... there are people out there who just aren't interested. I have several friends who love to come over every time I brew, drink some beers, watch the boil, chill out and talk, but they really aren't there to learn. And I'm cool with that.
I definitely think the reason for all this is there's just so much to learn about brewing. Even the simplest extract batch has a lot to explain and it can be overwhelming. Especially if you, as an experienced brewer, seem to just be rolling through the steps. Hell, I've tried explaining what I'm doing while teaching someone to brew and I just end up talking the entire time. It's like spouting off a textbook and they have to decide what information is important to listen to and what can be relearned later.
So these days I just invite people over, and let them feel it out for themselves. They ask questions, I give them some good, basic info. Then if they seem to really be into it after a couple batches, I offer to brew a batch for them if they buy the ingredients. We can do that a few times, and then start talking about getting their own equipment... congratulations, you're now a homebrewing jesus.