a good way to demotivate rare farm in pvp2 is to change the matchmaking system so that 2 players cant fight each other 2 times in a row, turning the farm considerably slower and more money/time consuming
for people who are patient enough, this wouldn't be a hindrance, plus it might hinder the people who actually want to play pvp but there's only 1 other person in pvp 2.
Also, I'm not quite sure how turning rares into relics would help people. I do set up farms occasionally for the "community" good, not only for newbies, but for people who've tried for weeks to get 6 of some rare but the special spins in arena just don't like them. Perhaps you'd advocate them farming for another 6 weeks? (of winter) While it might be a more extreme example, that does at least illustrate the point I'm trying to make.
Setting up farms doesn't take away from the experience as much as "grinding for 5 hours just to get 1 of the card I want" does. Farms don't even guarantee success in getting the designated rare. Plus they do require that I have at least farmed 6 of a rare to create a reliable farm. Certainly my effort counts for something? At least it means that I have more time to play and decided to make life easier for others?
Besides, beggers in chat are annoying and aren't people I'd set up a farm for
and isn't something that anyone can really help.