It sounds like you’re mixing up project managers and non-tech PMs, or you’ve only met PMs that weren’t very good at their job. I’m a non-tech PM and I haven’t encountered that problem. Our team knows I don’t know Code in depths but I am tech savvy and get what’s happening. It is not the PMs job to literally fix something technical that isn’t working, that’s up to the devs. IMHO. Being a good communicator helps a lot, no matter if tech or non-tech PM.