Software piracy didn't kill the Amiga. I'd say tons more Amigas were sold because of copy parties and quick-ish swapping.
But without copy parties, cracktros, and competition to release cool stuff first, no scene. It's what made the scene blossom from 3K cracktros with color cycle+scroller to groups making multi-disk megademos.
So for the scene it was good, but you can bet your ass small developers (the 1-4 people kind) got tired in the end selling 500-2000 copies of a game that took half a year to make. £30000 hardly covers 2 people's salary + rent a place to work in, not even mentioning packaging the games and marketing them.
So I think when it went from kiddies buying some £8 tape cos they didn't have a dual deck recorder
to kiddies having an X-copy night with a stash of 150 disks, devs ran out of money and they couldn't see enough money coming in, so they gave up and started another career.
Today, most kiddies don't have a "game capable" PC, and if they have a father who does, it's still a matter of setting up torrent tracker, possibly getting an invite, use a DVD burn/mount utility... if they don't know how, it's back to "knowing someone that will burn me a DVD" or maybe go to a LAN for 8yo etc etc.
Also, most games for kiddies are for consoles, PCs have "serious" games now. Roco Loco, platformers, sports games... for PC? nah.
Back then a regular family could have a 10yo who knew perfectly well how to copy a game in 3 minutes flat. Same family, copy a console game? Fageddabawdit! No surprise devs prefer consoles, and make more money.
Some generalisms here, but I hope you catch my drift
ps. My drift is that piracy killed Amiga software development - which eventually led to no new releases. Which led to BBStros over cracktros and stagnation of the scene in the end. (I'm sure the HOL guys can make a chart of #releases/year and see when it happened. Interesting stuff!)