Found my answer:
https://github.com/steemit/steem/issues/176
It is currently only applied to top-level posts. Comments lack the visibility to make much from spamming. We believe the spamming is being done by legitimate users trying to get eyes, not bots. At this time there is no reason to limit comments in this way. We also do not want users to comment less so their own posts can get paid more.

so ONLY for published posts and not comments