SSMTBs

What kind of riding are you guys doing at 2:1? That's what I have an using it winter commuting and messing about on gravel/fire roads, but some mates dragged me out 'mountain biking' a couple of weeks ago. It was single track but boggy, covered in roots and rocks and with steep parts and I found it completely unridable. I'll be the first to admit that I have no MTB skill or experience whatsoever, but I'm stronger and fitter than those I was riding with on the road. They were spinning away at walking pace fighting over the lumps, bumps and obstacles at 24:36 and I was grinding like crazy barely turning the pedals and as soon as I hit any resistance at all in the form of roots, rocks or ramps I just had no torque at all to push the bike over and I'd come to a dead stop and would have real trouble just getting going again. Even once we got out of the hard stuff onto a long, shallow, snow covered rocky incline I was out of the saddle the entire way grinding at maybe 35-40rpm with the back wheel spinning up now and again.

I can't figure out if I'm just missing something, using the bike in a way that's inappropriate for SS or other. These guys I've been riding with have been racing MTB, some at a fairly high level, for the last 20 years and if they're chosing ~1:2 for the trails, I don't see how it's possible to do the same at 2:1. But if I geared to 1:2 or thereabouts, it'd be useless for any mixed terrain ride where there may be flat/smooth riding.