The number of civilian designed autoloaders hasn't increased much. What has increased are the number of military based autoloaders - the M1, SKS, AK, AR, M14, FNFAL, Hk91/clones, etc. Price makes a point, too. In the day, I could by an HK91 for less - $45 less - than retail on the Rem 700.
Bolt action prices haven't gone down any, and you can get a $599 AR or $400 AK. When the significantly more complex autoloaders sell cheaper than the cheap and simple bolt guns, shooters see the bargain and buy them. Even at the higher prices of the major makers, AR's are taking shelf space away from boring old bolt guns.
As a hunter who was using a HK with Aimpoint in the '70's, it's not always about tradition, its sometimes about bucking it. Like fishing, you know the game has no clue about what you use, it's something you do because it makes it easier to use.