Why you say??
The answer is pretty easy.
Excellent quality rifle at a fraction of the price of a commercial variant.
Back in the day, lots of aftermarket accessories available to make it more presentable as a hunting rifle, at about half the price of a comparable sporter, IF you did the work yourself.
Many folks get all worked up over the ministrations of bubba on so many milsurps.
Back in the day, when those rifles were made available to the public, it provided an opportunity for a large segment of the population to acquire a firearm that was viable for hunting big game.
Believe it or not, hunting and shooting sports were mostly venues for the wealthy to pursue. After the Korean War, nations from all over the world were dumping huge stockpiles of mostly perfectly good service rifles, to raise much needed cash in a depression like economy and to clear out the warehouses for more modern replacement firearms.
I remember a fellow at International Firearms out of Montreal, telling Alan Lever about a deal where all they had to do was go in and pick up all of the arms at a facility in Europe and take them away. The paperwork wasn't nearly the hassle in 1965 it is now. Usually a handshake with a few thousand dollars of cash sealed the deal.
Most of those firearms ended up in the UK, where they were stripped down for parts. The best were set aside to be converted to sporters.
Only the best of the parts were kept. The rest went to the smelters. K98 stocks of every variant could be had in bundles of 5 for $5 plus shipping. Most were turned into all sorts of ugly decorations, such as table legs and crib boards.