They are just different business models. GW kept a steady cash flow through expansions and microtransactions.
Guild Wars isn't truly "free to play", you still have to buy the actual game, there is just no subscription fee.
Guild Wars only sells cosmetic items in the store such as costumes "gear skins" and weapon skins.
There is no "pay to win".
GW2 will employ the same business model.
What do you get in a subscription based game that you don't get in a F2P game? Not much honestly.
Anyway, I'm not a huge Guild Wars expert, in fact I didn't even really like the first game though I do own it.