normal people with families budget their gaming based upon the buy/trade paradigm
buy three games during a B2G1 sale, play them, trade them in towards the purchase of a new game, play new game, trade towards the purchase of another new game/bunch of used games, so on and so on
you cut out the avenue of those used sales, you cut out the majority of those new sales, it's pretty much that simple
everyone i know irl that isn't a gaming supernerd pays for almost all of their new games this way, and if the option is taken away from that group then they'll simply buy way fewer new games or quit gaming (because they are not as invested in it as we are, and they don't give a fuck about supporting a favorite company because they probably don't even know the names of the companies that make their games) and move on to some other hobby - or, the more likely scenario, they buy a tablet/ipod and start playing any of the thousands of $1/free games available
they're certainly not going to start paying $60+ they'll never be able to even partially recoup just because MS/Sony/Nintendo and a bunch of soapbox message board nerds who equate used games with piracy/the holocaust said they should
console and game companies depend on these people waaaaaaaaaay more than they seem to think they do, much moreso than they depend on new sales to people like us, and it will be a lesson in reality for the companies that dive headfirst into the "cut out used games altogether" business
the bitter, teary-eyed, handwringing "why consoles are dying/what happened?" analysis articles and threads in a few years will be hilarious, though