Because Audis are so well known as an attainable first vehicle. Cheap to service too.
Imports, AWD, Cargo Space. Remember those things and you're set.
Assuming you buy used and if you can afford to, also keep in mind that things like belts and gaskets start to go at about 10 years old and if you buy it with more than 200000 km on it you probably won't get much when you want to sell it. Oh and have it inspected or you could be boiling away in used car repair hell right quick.