Adding stats is a whole balance issue that companies find extremely difficult to do with skills.
Different stats and skills together is HARD to balance.
Look at dragonica, even with just skills they have people crying over builds builds builds when it's freaking obvious and you get free resets each job change, they still don't know what they are doing. If you add stats into this game it will be a mess.
Look at wow, with skills you still get noobs that choose incorrect ones and pay gold to keep changing skills. If you add stats their brains will explode.
Look at ragnarok, skills + stat points. Think about the number of reset npcs you get in private servers, and how SCREWED people were when they played on 1x rates of public servers. There were screwed up classes everywhere, and this didn't change much until reset npcs were added.
Therefore, with stat points and skill points, the balancing issue is so extreme that developers would rather spend time adding content (or lack thereof... *cough* dragonica *cough*) rather than spend time balancing out classes and answering noobs questions of
"halp!! which build is best??!!? Which class is best for pve?? Help!!!"
Why you ask??
Pretty obvious why.



