They are offset quite a bit from the belt, have been known to jamb and break, and have contributed to several shooters finding their trigger fingers engaged in pulling the trigger prior to intending to.
I believe you are describing the "duty" model that would more likely be worn by a LEO rather than a civilian. The offset you speak of gets the handgun out and away from the body, waist length cut heavy jacket, etc. and also lowers the holster to allow it to extend more below the belt and the bullet proof vest. A friend of mine has one of these and for what it is worth, the offset portion can be removed.
I have two Blackhawk Serpa holsters and like the active retention. One for my XDs, the other for my Series 70. Neither have exhibited the problems, "jam and break", that you speak of, albeit I am just one data point. I would appreciate seeing the stats, web pages, reports, etc. you are referring to where this is becoming a problem.
As for "pulling the trigger prior to intending to".....as someone else mentioned, that is a shooter problem. My XD's trigger is completely covered by the Serpa. If someone is shooting at their foot while presenting, then they need to learn the basics of running a handgun, IMO, before given the chance to shoot at themselves again.
It is not a great CCW holster although I've carried with mine a number of times using a loose fitting wool shirt. I prefer an OWB leather Galco which is a bit better for me.