I usually take a benign view of embedded links, especially links to non-Medium pages. If someone takes the time to write a thoughtful comment and attaches a link to their own article on Medium, I'm okay with that.

OTOH, when I get a one-line comment and a link to the commenter's story, I consider that rude self-promotion. You yourself called it laziness and admitted you were putting that same link into "comments" on as many as 20 other writers' stories. How is that not self-promotion?

I had such an exchange some weeks ago--it could have been with you, but I don't remember. Very brief comments, multiple links, and the exact verbatim justification: "I've had numerous positive responses . . . This is the first negative one."

Sincere exchange of views is, and should be, welcome on a platform such as this one. But no one likes a spammer.