Charging for a catalog keeps most of the looky, looky, crowd away.
Just like when Snap on would advertise in Hot Rod magazine, can you imagine the flood of requests they got from high school Harries, and other assorted dreamers?
Another good example is the McMaster-Carr catalog, can you imagine what that costs to print, then imagine the demand if they were to hand them out to every Tom's, ****, is Harry, that just has to have one. 99.9 percent of the recipients would NEVER be heard from again. The same can be said for Grainger.
In fact, IIRC, most of the speed equipment companies did charge for their catalogs, I imagine for that very reason. The issue is solved by refunding the price of the catalog with the first order.
If I want a free catalog, I don't mind buying something in exchange.
As it is, my 'off-brand' tool (Cornwell and MAC), and my hardware, or specialty catalogs came from eBay, as did my Snap on industrial catalog. My Snap on and Matco catalogs came from the dealer, as do my NAPA ones.