I'll just share my exprience. I started playing in the 5th grade. Took lessons until 8th grade. My teachers would try to teach me theory and how to read, but as a kid I didn't want to bother with the extra "homework" of learning that. So all I learned was tabs. Fast forward to today (I'm 24, so about 13 years later) and I regret not learning theory. Sure I have gotten by these many years with just tabs, like people mentioned, there are guitar legends out there who don't know theory or how to read music. But now I WANT to learn it, but it is harder since I'm a little older and now have to balance my time between other things.

So I say learn it and start early. You can't regret knowing theory, but you CAN regret NOT knowing it.