From my experience, D2 is a T sided map in competitive play but CT sided in random pugs.
Competitive play being 5v5, it is hard for the CT to cover both spots equally and a typical strategy involves overloading one spot with 3, having a floater near spawn and a floater/watcher of the other spot.
Pug play is just a killboard and you will invariably find several T who camp their spawn in fear of dying and the numbers are generally higher than 5v5 which allows CT to cover both spots effectively.
I remember CT rush strats, described above, but only if we got the good spawn points, if not, it wasn't worth it.