I watched this video on youtube explaining all the things available in the store using Gems. Gems are the same as Turbine points!
You can earn plenty of gems in guild wars by doing quests, pvp and dungeons.
You can earn hardly any turbine points only by grinding deeds that take hours and hours.
Gems are used to buy things that you can also earn in game by doing quest, pvp and dungeons - once again E.g (morale potions, dyes for clothing etc...)
Turbine points are used to buy items that are extremely rare and things are not even available in the real world E.g ( tome of defence -5% incoming damage)
Gems are used to supplement a persons time
Turbine points are used to supplement a persons skill.
Rant over. In conclusion I disagree GW2 is another p2w game.