Deal with badly written code

Since I want to be a good programmer, I developed a precise coding style, and I do my best to write elegant code, however from time to time I find myself messing with poorly written code. This reduces my enthusiasm, and I feel the instinct of fixing it ...but in real life you don't have the time for fixing someone else's code, and you have to put a patch on it.

On the long term this leads to a world-wide growing code base which sucks and keeps sucking... and this drives me mad! How do you handle this problem?

tl;dr: We have a lot of shit to work with. How can you survive?

>>4
Good point: typically this happens in an academic environment, where they put retard students (or "researchers") who just know Java at doing Real Man's work.

Also I'm not totally happy with putting the garbage under the hood: sooner or later the badly written code shows up (say because of a bug or because of some awful memory leak.