I want the feel of soloing my job to level 10-15 then having to go to the dunes the first time and get in a group and the whole game pretty much changes as I have to learn how to play my job properly, what to do and what not to do and how to setup skillchains and magic bursts... the stuff youll never get from solo play... since its pretty just just (spam all your attacks and hope mob dies before you... and heal is necessary.. if you can)..
in a solo environment you learn nothing of hate control, over healing (i.e as not to pull hate from tank) coordinating attacks for sc and mb, keeping mobs debuffed and party buffed, distances, etc etc. Sure you might say "well when you go in instanced dungeons or raids youll be in a group so youll know that stuff. Umm at that time its too late, thats something you should know BEFORE you enter a raid/dungeon... that would be like dropping me off in a warzone before teaching me how to properly use a gun and hope I can figure it out before my face gets shot off.