One of my favorite recurring subjects is how bad seventies Fenders are/were. I started playing in the 70's when "common knowledge" was that anything past pre-CBS was crap. Except it wasn't in the experience of myself and a lot of other bassists, particularly those interested in Jazz basses.
Pre-CBS basses typically didn't sound like 70's Jazzes. At all.
QC players freaked out about neck pocket gap. oh the pain. The actual effect on the sound and playability was what?
Weight was an automatic demerit... except for people who weren't bothered by it.
I smiled at the bowed necks comment earlier in the thread because it highlighted a huge issue that may not be as prevalent now as it was in the seventies: setup, while clearly not permanent, was a huge issue for most bassists because we didn't know what the hell we were doing when it came to it. Trussrods were an absolute mystery... you turned them in one of three directions in small increments, put the bass in the living room near a mayonnaise jar and left it for a day (or two?) and checked it for some sort of movement. Lather, rinse, repeat

. If you had the stones to actually try it you might break your bass.
I took my 68 Jazz to a tech in the 80's, the first and only time I did it. I wanted my action lower. A week later, the bass was done... and the action was higher. Because he said that was factory spec. I really started to dig into Guitar Player magazine, read Dan Erlewine columns and educated myself on how my instrument works and it really paid off. Suddenly basses that "sucked" didn't. And the basses didn't change.
It is the rare exception that I find an older Fender Jazz that has actual real issues that aren't easily addressed. I actually like doing a full setup and bringing one up to snuff. No, I couldn't care less about a neck gap, the necks I've dealt with don't move and I've yet to hear a gap. I had no problem with the finishes which were far more durable than earlier stuff. I can play heavier basses so that's another non-issue. One man's trash...
I agree on the 80's basses, when IIRC Fender was trying different stuff like putting the Kubicki package in Jazz basses. I don't really remember build quality issues, just didn't care for the straying from what killed in the 70's. A lot of people are extremely happy with 70's Jazzes including myself.