The game can end in one of two ways: either you fight your way to tenure, or else you drop out at any point along the way (by choice or by force) and take a job somewhere else. At that point, you'll be rated based on your level of completion and your expected lifetime earnings.
Like in real life, going for tenure is a gamble - if you fail, you're missing out on a lot of money you could've earned through an industry job if you had been working. It only pays off if you make it all the way. Sometimes a safer strategy is to get some marketable skills and drop out!