This was before the Internet was really a thing, so even after the copy protection was cracked pirating software was still a hassle. Pirate BBSes took some effort to discover, and often had download quota systems you'd have to play along with. Even after that, you couldn't download a file without tying up the phone line and if a local BBS didn't exist you'd need to pay long distance charges, both of which risked the wrath of your parents.
So the "dedicated attackers" needed to be somewhat more dedicated, and were therefore rather less common. You could get a lot further by just preventing casual floppy copying, which was sometimes sufficient to discourage friends copying a game instead of buying a copy for each of themselves.
By contrast, warez present essentially zero hassle nowadays. That dramatically alters the equation.