I'm sorry, but anyone who thinks that rolling for stats would have been a good idea for DDO clearly does not have a good understanding of game balance.
I used to play in a MUD that let people roll for their stats. The result? Everyone used autoroller programs to roll for hours, days, or even weeks to generate thousands upon thousands of results until they got the super high rare numbers that they wanted. If you used any kind of rolling system in this game, people would just roll over and over until everyone had a ridiculously high point character.