I would certainly think about the other replies that people have given, but allow me to give you a slightly different view of your situation and the industry as a whole. When I was first starting out I wrote in Basic and then very shortly after in C. From there I moved to Visual Basic and I thought "Wow! What am I doing? I'm not comfortable in this. I am much more efficient and happy in C or my old Basic. This is the worst idea ever!" But, I did it. Then there was C++, .Net in various flavors, and Java also in various flavors. Each time I thought this language/framework stinks! It's actually a relatively common thing to think from a developers standpoint. In very recent years I have learned Ruby and Rails as well as some Python and Django. Then a few weeks ago a very lucrative and fun contract came up in PHP (of all things)! At this point I feel very comfortable with three ideas in my career that might be useful to you:

1) There is no perfect language and all of them can do amazing things with the right person (me! and heck you too!) behind them.

2) Sometimes I will be less effective when I am starting in a new or changing environment but half the fun is finding where I can lead and make great changes for the users.

3) Offshoring will exacerbate issues these issues but my ability to make substantial impacts increases exponentially with the amount of offshoring that is going on within an organization. I capitalize on this.

Obviously, if you are just tired of being there and don't want to stay, then leave. Though I would suggest like either that you find a job before you quit your current position. However, if the whole code base needs a good refactoring, by all means, make an impact! Start in a small piece and make a difference. Start to lead.