For many people, those things are pretty cost prohibitive, and as Ramy pointed out, an Ipad doesn't fit too well in a cockpit. I was actually in the initial stages of designing a low-cost AHRS for "get-down" situations, but ran out of time to put one in. Not that glider pilots don't encounter $1000 costs, but i'm not sure "phenomenally cheap" is the term those of us not flying 6-figure glass would use to describe the current AHRS market.

If you are not pushing the bounds of safety and are properly adjusting for the conditions in flight, there really shouldn't be a need for an AHRS. Yes, i could have used one on this flight, but at that point i was already 2 bad decisions deep. More equipment will not breed better decision making, it breeds more data, and in many cases lazy pilots who have another crutch. Saying people should buy more equipment is akin to blaming your botched off-field landings on not having a higher performance glider.