Signed copies protect you from litigation in court, not loss of brand value in the court of public opinion. Plenty of people bitten by it will just never use a backup product from you again, and every time apple sneezes a flurry of journalists are there to document it.

I guess the idea here is to make enabling the option enough of a pain so that only people who need it are going to use it, and button smashers will be spared.