There’s another part of this story that Wikipedia leaves out
The other two original Power Mac models had the code names “Piltdown Man” and “Cold Fusion”—not exactly the sort of thing someone like Sagan would want to be implicitly associated with.
After a few weeks of excitement over the Fleischmann/Pons thing, cold fusion has never since been taken seriously by fusion researchers. It's a dead idea as far as I'm aware.
Based purely on the Wikipedia description, Sagan's request seems reasonable, from a moral perspective at least. I have no idea why Apple (or its engineers) would be so butthurt about it.
Because it was just a silly internal code name for an unreleased product and Carl Sagon was just being a killjoy to his own fans. That he continued to escalate with lawsuits makes him look ridiculous frankly...
His reason was "concerned that it would become a product endorsement," and it was after the name was "publicized," which sounds reasonable to me.
The joy can only go so far, IMHO. If the namesake person asked for it, you comply—pretty simple. I can totally see why people aren’t comfortable with their name being used without permission, even without the endorsement concern.
So he was supposed to just accept being called "Butt-Head Astronomer"? Sure, I’d respect him more if he did, but I’m not going to call him pompous or having a big ego just because he didn’t.
Yes, that's the nature of free speech. Butt-Head is clearly a statement of opinion and not of fact. Apple is entitled to communicate their opinion of people. It is clearly not defamatory.