Spam was mentioned because it's a brand name that became generic because it wasn't protected aggressively enough. Coke, Xerox, and Kleenex are other classic examples of brands that are commonly used generically, and the company owning their trademarks must aggressively send threats (that they rarely follow up on) just out of legal necessity.

Spam very aggressively protects their trademark. So aggressively that it lost a trademark lawsuit against Spam Arrest. (They lost cause people don't get food and junk mail confused)

Indeed, Hormel once sent nastygrams about their trademark to the ASF over our Apache SpamAssassin software. Trademark owners can ask everyone to use or not use their own names. Actually going to court - or actually winning - is far far rarer.