"people have a negative connotation to the word Marxism" absolutely has baked-in implications, and an argument left unsaid, even in total isolation
if i say to you "people think the word nazi has negative connotations", then even with no other context then obviously you'd conclude that i'm a nazi freak
the post doesn't make any justification for the ideas being sound and good, it says they sound good
i don't think this post's subtext is as simple as the interpretation you're providing