With all the electronic methods out there,,, it comes down to costs. Ruger does print some catalogs,,, BUT,, in much less numbers than before. Plus, due to the constant addition of new guns, or different models, by the time a catalog gets printed & put out,,, it's "out of date."
At SHOT & the NRA Convention, you can get a catalog. Or, you can see if a bigger stocking Ruger dealer has some.
Oh, they also do a limited printing of an international catalog too. I got both at SHOT this year. The international one was VERY limited to find. I had to ask a specific person for one. It actually has a few less models in it than the American catalog,,, but is printed on heavier paper stock.