Bach did this for a lot of his music, and he wrote some pretty hip stuff. Some times it can sound very mathmatical, but everything can't be straight from the heart. Personally I like music that contains an even amount of emotion and technicallity, too much of either or can get boring.
As well as the theory vrs song thing I think it depends on your personality and learning style. As for myself, I like to know as much as possible about whatever I set out to accomplish, whether it be computers, music, or fitness, I don't think knowledge hurts you. But I know I like to see things make sense on paper before I apply it to guitar, or computer, or whatever.
Learning theory will not styfle your creativity, and the long run it will expand it greatly. Over my years of playing/studying I've learned you can apply any note over any chord if you approach it correctly. The process it took to get to this point was long (to not only understand it but hear it). But the pt is it is a process, and the more you understand how things work the more creative you will become.