they are just hurting themselves. they make the game worse for something that will only make it better for most players. IRL, 90% of people i know irl that play, or have played have bought rsgp.
this is the reason i wont be playing mechscape when it comes out. jagex will "learn" from the RS "mistakes" and they will make mechscape a rule filled, non cheating piece of shit. its not like were trying to fuck over jagex by buying rsgp. shit, if they were smart they would sell rsgp. since it would be the safest way to buy rsgp they could sell it for like $8 per mill and still get plenty of customers.
the economy of rs depends on at least some RWT.