USA proof sets

[Sword 1,368]

When I first started collecting coins as a teenager, I particularly liked my USA proof set. Out of sentiments, I have just brought a 1992 silver proof set on eBay. I am a little surprised that the older proof sets are so unloved and my cost me £14.50 + postage. Is the excessively high mintage (well over a million) the only reason for the lack of desirability? The designs are generally rather nice. 

[Mr T 171]

I don't really track US coins but yeah probably the high mintage would be part of it.

I'd assume that collectors are very much divided (like here) into classic (1960s or earlier) and modern (alphabet sets/state quarters) and maybe these sets fall in between.

[Sword 1,368]

Even the sets from the 1950s can be picked up relatively cheaply. I guess it is a change from collecting British coinage as the obverse portraits are all different.