The OP is seriously underestimating the value of virtual currency in games like this. You say it has no value outside of the game? Then Why do RMT sites exist?

What SE has done is basically admit they have no real method of identifying people using RMT so goin forward thy have a set a precedent to just take people's Gil if they had something purchased from them with RMT Gil. Man that sure makes me want to sell stuff on the MB. Hey lets all go level a DoL or DoH class to make Gil so SE can take it from us whenever they deem necessary. Yea that sounds fun.

The worst part about what SE did is install doubt into every player on how the game operates. In any game you play, you play with the assumption that money you make in in game will be there the next time you log in unless your hacked or are involved in unsactioned activities. But in FFXIV who knows? They will come take your Gil at anytime even if you have played the game 100% legit.