I'm just curious as to why so many commuters chose MTB bikes. Around here, almost all commuters use them, and it seems like most on this forum choose MTBs too.

I have a mountain bike and several road bikes, and I don't like the way the MTB handles on the road. It's inefficient and slow, but the upright position does provide a better view of traffic.

Most entry-level commuter bikes are based on hybrid or MTB frames, so it does seem that the market demands an MTB style bike for commuting (in general).

Anyway, I'm not trying to "diss" MTBs or start a flame war, I'm genuinely curious.