Not sure what all the fuss is about.
If you use the holster as-directed (which I do), it works as advertised. Your trigger finger *should* come out parallel to the slide/frame and outside the trigger guard. If you 'hook' your finger to disable the active retention lock on the SERPA, then you either didn't pay attention, or given the size of the firearm, carry position, hand size and maybe other environmental variable, the SERPA product line isn't the right piece of equipment for you.
Take careful note of the last phrase..."isn't the right piece of equipment for you." There are thousands and thousands of holster options out there. I tend to buy from known manufacturers with solid reputations for quality. Just because Holster A works well with Firearm B for Shooter C, does not mean the same holds true for Shooters D and E. I've bought plenty of name-brand holsters that just did not work out well for me for any number of reasons. They either get returned, gifted or left in a box to rot.
The more I read about the SERPA "issue", the more and more I think it's a PEBKAC-type matter, and not a design philosophy or engineering problem.