Yeah, you're wrong. Calling here is good and is almost always better than jamming. In general, calling 15bb deep is really good and should be your most frequent choice by far.
As for 3b shove math, there are a lot of calculators you can use. Paid ones include ICMIZER, Holdem Resources, Coffeecalcs. There's a free one on husng.com as well.
If your opponent is really opening ATC, and calls 40% of the the time, then yes 85% of your range is better shoved than folded--still many can call more profitably. Also chances are really high they're not actually minraising ATC
If they minraise 80% but call top 40%, then about 50% hands are unprofitable shoves even compared to folding. J8o is about break-even compared to folding, while flatting will do significantly better.