Comment by Desafinado

I'm not sure I'm in full agreement with this. Yes your network has a big impact on your success, but your network is going to be a lot more helpful if you're a skilled developer who delivers.

Put another way, if you put in the effort to become a consistently excellent developer, that's most definitely not going to hurt your career prospects. If you're mediocre and cause problems people will be less likely to refer you.