That's what 'transactional' means... it's supposed to be used for the end or beginning of a transaction (reset password, receipt for a purchase, things like that...)
No, that is not what transactional mail means, you're wrong.
Things like friend requests are also transactional email by definition. So are those "you left your cart behind, want to complete the purchase?". That doesn't mean that you asked to receive it.
Instead of being pedantic about it lets give it another name then. Whatever we call this new category of email that does not include password resets and does include friend requests and abandonment emails - don't send them 4x per day.
Come on, sometimes it's better to be understood than to be right. Fuck the definition.
That's what 'transactional' means... it's supposed to be used for the end or beginning of a transaction (reset password, receipt for a purchase, things like that...)