Lots of people like having target gun triggers on a defensive weapon. Yet the standard worldwide over the last 100 years is a minimum 6 pound pull and usually 8 on issued weapons to armed forces.
I hear a lot about the BG380 being a good carry gun and it's 12 pounds.
The point being that trigger weight does not make it "good" or "bad." In point of fact Massad Ayoob took up that challenge and competed in a tactical shoot with a Glock and NY 10 pound trigger. The result was he won the championship. It has a lot to do with the shooter's expertise.
Let me add salt to this dutch rub by mentioning the S&W automatics introduced in 1954. They were largely DA triggers first shot - a long and heavy pull which would then reset to SA. Those guns went thru three generations with tens of thousands issued to police departments and they are now becoming collectible. All those cops didn't have major issues with the triggers on those guns, they qualified. For the most part back then they were shooting as often as most of us.
As they turn up as police trade-ins the bulk of the internet posts are from experienced users who carried them for years - even decades - and they have no problems with them. Why? They figured it out because they had to, and once used to it, no further problems.
It's much the same as getting broken to harness. Young colts don't care for it, working studs don't give it any thought.
Your grandpa just needs to try the trigger himself and come up with his own decision. We can't do that from here.