It may have been very easy to pirate but in my opinion, the main thing Autodesk did was two-fold. 1. Give steep educational discounts to engineering and drafting programs so that AutoCAD was the defacto CAD program new grads understood. These were fairly easy to pirate if one wanted to, but that was a secondary feature to the proliferation of a generation of engineering graduates who could be functional in AutoCAD with minimal training. 2. Offered AutoCAD LT for small businesses that wouldn’t break the bank (and wasn’t completely nerfed of all useful features) and allow them to stop pirating and license a legit copy of AutoCAD.
In the Bay Area (Adesk’s home), Acad was prolific and it was not uncommon for a generic 80286/80287 PC (circ ~1982) to have Acad pre-installed or with it loaded on a 5 1/4" floppy (with the other software a generic PC added).
Adesk did very little to discourage this because of laissez-faire and that “bootleg” era.
Acad was inferior to what was available then and it was easy for users to get/copy/install (it was every where, at swap meets and flea markets).
Adesk was in the right time and the right place and became what they are today, sadly, that name is still present. <()>