In my opinion, what killed the Amiga was Commodore's management screwups.. not keeping the Amiga hardware current enough which allowed the PC to take over.
Yes, I did pirate games, as many others did, but most of the time the disks were corrupt or had problems on my A1200 anyway. I seem to remember hacking into quite a few cracked games to fix A1200-related problems
The whole try-before-you-buy thing really works, and good demo's on coverdisks really helped with that. For example, I bought Hired Guns and Worms, solely because the coverdisk demo's impressed me so much. Hired Guns still does impress me, I've just managed to get a 100% cracked version onto my PC to play under WinUAE (I figure I'm allowed - I did buy the original after all!)
I actually remember a friend of mine taking the piss out of me because I bought hired guns. "You paid all that money when you couldve just got a pirate copy" he said. Two weeks later, he was asking me if he could copy my Disk 3 because his pirate version was corrupt... a week after that, he found the "THIS IS AN ILLEGAL COPY" trap in his saved games