I haven't used Ada in a commercial setting, unfortunately. I was never that involved with comp.lang.ada so I can't really comment there. However I never really got that impression from freenode #ada. Based on what I heard there, I'd describe it more like "if you don't know that you need it, you don't need it." I also got the impression comp.lang.ada tended to be a bit more um... conservative, if you will. I'm not so surprised to hear they were more inclined to have a commercial license.

Personally speaking with my own experiences and what I saw on #ada I'd be comfortable going without a commercial license. I've only ever seen problems with somewhat odd situations, and I'm pretty sure all of them produced a bug box (compiler error message) so at least I was aware of the situation. And Ada often has multiple reasonable ways of doing something, so even if the odd/clever thing causes an error it's unlikely to be a blocker. Mostly it means I would have to put up with usage that's a little more not to my taste.