Before I tell you that it is reckless, let me ask you what you think of people who drive one to two tonnes of steel while eating, drinking or talking on a cell phone? Or those who drive too fast for conditions, without headlights on in the dark and the rain, with vehicles in poor maintennance? And then you have the people who drive under the influence of drugs like alcohol.
Which can cause more damage? a tank blowing up, or a car losing control? (I know the numbers will show more people die in car accidents, but we can't use those as more people drive cars than own scubatanks)
So while yes, it might be reckless, it seems to be decently safe, or should I say, it tends to not kill people, so we do it. I'd be quite upset if a shop didn't fill my LP steels to atleast 3100. (that is if I owned any. As it is, I use HP aluminums and I balk at any fill lower than 3600, but the tanks are designed for 3300 cold and they cool off to 33 when hot filled to 36.)