That's really not what the "spam" button is for, and you probably know that. You most certainly could turn those emails off - just go to email settings and click "introductions only". There's even a link at the bottom of each email to adjust your settings.
Don't make it more likely that my LinkedIn messages get marked as spam through Spamhaus or gmail algorithms just because you don't want to click twice to unsubscribe or prove some kind of hate-point.
(source: used to take care of an opt-in service's email spam rankings and had tons of people not use the "easy unsubscribe", and others angry they couldn't get their expected/important notifications sometimes when it got sent to a spam folder)