I ride with road pedals but they are also double sided. I couldn't stand single-sided pedals. I don't see a problem with people using any pedal they want as long as they're happy with them. As far as Speedplay Frogs go, I used to have them on my roadbike before switching over to the Zeros. I know plenty of people who use them on roadbikes and actually very few of the MTBers I know of would use them on their MTBs. I wouldn't consider them a viable choice for an MTB pedal to be honest. I think they'd make great touring pedals though.