I know Amiga got popular in the local computerclub where I was since most parents saw that not only it was a great machine for their kids, but that software was abundantly available at no extra price, unlike the Sega & other Jap console stuff that was around, which had the hidden price of paying a lot more than the console itself to keep your kids happy. So it was good for the Amiga there was piracy, it allowed to be accessible for most normal folks, so many 500s were sold that way.
And the more hardware is out there, the more chances a software company can sell more copies, despite being pirated a lot. Of course it can kill a company and it is theft, but I would feel more comfortable writing a game for a machine of which 100,000 are sold and is easy pirate-able then writing it for a console of which 5,000 are sold and is very hard to pirate.
Amiga for me was the logical next step after C64, and the copying of games was part of the "necessary tradition". Most games I would not even have bothered having/buying, unless I had them easily for free, moreover since I did not have the money to buy them (my parents bought the hardware for me). And in my local village, nowhere were Amiga software shops, you had to drive (=find a driver) to a city 20 miles away to see any $$$ Amiga-software shop. Magazines were the primary source of info of new games, not the shops... gee, imagine internet those days! (I never was in the BBS or cracker scene, so I had to find all out by friends and mags what was happening.
It was a nice period, and I only bought some productivity software and wrote some myself, but games were more like some 'freebie bonus' experience, the Amiga was much more interesting than just games for me. I did play a lot of different games to see what was new, but only a few attracted me enough to spend more than 30 minutes with it, and since I already had them at the moment of discovery, why bother go buy them afterwards? (and 99% of all my fave games were from 1987-1989 only!)
Oh well, I do not try to say piracy is ok, it is not and never will, but for most souls it was the only way to have cheap entertainment, are we now criminals who killed Amiga? No, I would have never bought one if I had to pay 25 quid for each floppy I wanted to boot.
Somewhat similar and related, the same is the case with Sattelite TV. Today I read an article on SAT TV providers who make first their encryption VERY hard to crack, but then unofficially leak their decryption codes months before switching to an uncrackable system, just to: a) sell their stock of old vulnerable decoders and, b) to create a public who will buy the subscription once they realize their pirate decoders are worthless when the new encryption system is in place, but saw enough during the previous months with the leaked decryption methods/keys to decide it is worth buying... Not a bad strategy I think...
Amiga died because the manufacturer stopped innovating, made a lot of costly mistakes (so all this nothing to do with piracy) and left their user base with nothing to re-motivate themselves, so they left bit by bit, seller & buyer, towards other platforms.