I know guys who didn't do the CFI thing and guys who did. There are food and bad pilots from both groups. The good pilots bring something from each of their backgrounds.
The biggest disadvantage to not doing your CFI is that when you finish your commercial certificate with 250 hours, your job options will be very limited. The CFI option opens lots of jobs and you learn something by being a CFI. You will also learn lots of things in non-CFI jobs but you get my point.