Ford possesses a dominant, persistent, and increasing share of the world- wide market for Shell-compatible vehicles. Every year for the last decade, Ford's share of the market for Shell-compatible vehicles has stood above ninety percent. For the last couple of years the figure has been at least ninety-five percent, and analysts project that the share will climb even higher over the next few years. Even if Porsche's vehicles were included in the relevant market, Ford's share would still stand well above eighty percent.

Only true if we ignore all other vehicles, but so what?

We can take the car analogy further by considering radios.
OMG!!! Citroen bundles a non-standard radio with their vehicle! We must sue them into oblivion and force them to unbundle their radio and sell cars without radios, or with a selection of several.

Better to make heavy use of the spam option... This tells your email provider that it's spam, so that their spam filters will learn and improve.

But anyway, never click a link in a spam email. Even if the criminals say they'll unsubscribe you if you do. Spammers have a habit of not being entirely scrupulous...
The purpose of the opt out link in a spam email is to tell the spammer that your email address is actively used.
(On a side note, it is also possible for them to detect this automatically when you open the email, if your email client displays images by default. This is why Gmail doesn't display images until you tell it to, unless you whitelist a specific sender.)