If you read the full interview, which is on the second page, he says this:

You haven’t really appeared in any music videos or performed live in awhile:
Yeah. Well, when you’re at this age you go through this thing. Well, me personally—I go through this…do I still wanna do it? I’ve done it for years, since I was like 17, 18 years old. You try to find what you love to do, which I’m doing now. I never really knew if I wanted to step back into the arena, if I wanted to really be in the business. When I would get these calls from artists, I felt great about it. At the same time, I never wanted to tease people in a way where I’d be in the video and then they won’t see me for another ten years or anything. So, you know, when I would talk to these artists and we’d agree that we’d do these songs, we would all be in agreement that it was just vocals. There was no visual or anything. Every artist I work with from Beyonce, from Young Jeezy and Jay-Z, from BoB, it was all understood before my first rhyme was written that there was going to be no videos. And I always felt like—you know, I haven’t been in even in a video with Big Boi—it’s kind of disrespectful of me if I can just jump in a video with a new artist and I haven’t even jumped in the video with my own partner. So I always said, I’m not going to fully jump back into it until I really do it. I’m not going to play around. If it’s not my project or an Outkast thing, or you know, if I’m supporting Big Boi, then it just didn’t make sense for me. It just didn’t feel right doing it. So it’s a loyalty to myself and trying to make sure I really wanted to be in the business again.