A post is simply too long or too densely packed to read the whole thing, but the general topic is of interest... and a comment without reading the whole post should be just fine.
A one word comment is appropriate
Arguing with someone is important to attempt to convince
The goal of posting is let off steam (no longer steem)
Being popular is not the goal
Sharing one's thoughts causes someone else to become offended
Forced/Enforced Happy Engagement is just not real engagement
RE: The 9 Do’s And Don’ts For Better Engagements