My take on this is that after the pre-CBS era everything sucked according to some people... whether they actually did or not was unimportant. It was far easier to make the generalization. So when the "experts" filled others' heads with that stuff, many of them believed it. There weren't a lot of skeptics then and there are people who've remained as unskeptical now.
In the meantime a whole generation of bassists came up who weren't glued to an Alder P bass. We weren't nostalgic for that tone so when we didn't get it out of heavy Ash basses... so what.
There are people who can describe chapter and verse just about everything that was "wrong" about the 70's Fenders. Fortunately there were others who'd just pick up the instrument, play... and sound fine.
This goes well beyond just picking up and playing an instrument. This is about finding a "match" for you. There weren't collectors after these things- Fifteen years ago, they were the "used" instruments that sat hanging on the wall for months for $400. Because there wasn't a collector influence on the pricing of the instruments- the price reflected their actual desirability to players- and their availability at those prices speaks about their actual desirability.
It's not so much 'experts filling people's heads with what's wrong with an instrument,' but more of people finding the general characteristics of a "good instrument" at odds with what 70s instruments fundamentally are. There's something to be said if an instrument "speaks" to you, but if what an "expert" says is "wrong" with a 70s instrument is "wrong" to you- then there's little to owning the instrument except for the "prestige" of owning a 35 year old instrument.
If you like 12 pound instruments- cool. I don't. Even when I was a 23 year old stud I didn't even want a 14 pound Travis Bean pulling my shoulder down. The "prestige" of owning Travis Bean S/N 117 wore off after a couple of months of playing the guitar.
If you like the feel of the thick poly finish- cool. I don't.
If you like the idea of the 3 bolt neck joint- and Fender's execution of that idea- cool. I don't. One of the most embarrassing guitars I ever had was either a 72 or 74 Telecaster Custom. That neck joint was so bad that if you strummed the guitar somewhat vigorously, the neck would slip- you'd be out of tune until you slapped upward on the neck while holding the body steady. Useless.
Add to that the leisure suit tacky big headstock on Strats...
The 70s were a time when there were different ideas of what makes a "good" instrument. Mass and Brass were in. A 12 pound instrument meant it gives great "sustain." These are generally ideas that have been relegated to obscurity. If you'll take note that most characteristic features of the 70s Fenders are gone from standard production today- and more closely resemble 60s instruments in weight and appearance.
My theory is there are more people playing now than there ever have been. Whether it's the availability of playable "cheap" gear or that the whole "play guitar and be cool" thing is perpetuated so much- I can't imagine a videogame about playing guitar being successful 10, 15 or 20 years ago. Boomers are more financially set, and may be picking up playing again, or for the first time. Fifteen years ago, this area would have never supported a Guitar Center. There was one big shop and several "mom & pops" that were never too busy. Now, there's a GC, that big store and those "mom & pops" are filled with entry level garbage where the "old" and "used" guitars used to hang.
Even 10 years ago, collectors weren't rabidly after pre-CBS "player" instruments- but once the clean ones were snapped up, there were only refins and repairs. Once those got snapped up- prices really jumped. Then the "next best thing" was a 70s guitar. Only difference is- they're not the same thing.
If you grow up with a 70s instrument, or find it's characteristics suitable to you- great. But 9 times out of 10 you'll hear "look at my cool, old, 'vintage' bass." Not "this thing is the most resonant pieces of wood you'll ever feel."
The collector pricing BS ruined the fun of "vintage" guitars for me. Although it may seem foreign, but there was a time, not all that long ago, that you could own a good "player" pre-CBS bass for under a grand. You could get beater 1950s Les Paul Juniors for $500 and clean ones for under a grand. You could play and own these instruments and figure out what you liked and didn't like. You didn't have a 70s Fender to be cool or to have a great instrument- you had one because you were broke.
You want to see how fast that collector pricing thing came about- Check out the Les Paul Forum. I remember around 2000/2001 the going rate on a "'Burst" was around 80-90K. Joe Ganzler went all ape and spent 125K on his burst- they're north of 200K now. Within a span of 10 years.
. I guess it must be supply and demand. Generally speaking, IMO the majority of the CBS-era Fenders I've played and owned weren't on par with the pre-CBS instruments that I've played from a tone and construction standpoint. -Not to say that every pre-CBS bass that I've played was fantastic, but for the most part, I found them to be a superior instrument.
. I'm with Mojo-Man on this: The vintage Fender sound can be found in USA Lakland and Lull basses for a fraction of the price of a pre-CBS Fender. And judging from the sound of Nordstrand pickups, I feel it's safe to assume that Carey Nordstrand can build a Nordy with a sweet, vintage sound 
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