In this answer I used the blockquote markdown syntax to emphasize the few sentences that contain the gist of the answer. Federico Poloni commented that this is bad practice and his comment got some upvotes. On the other hand, I've seen others using the same practice, see, e.g. this answer, this question or this question So I like to ask:

Is is bad practice to use the blockquote syntax to highlight a tl;dr?

(Oops, I did it again…)

A bit related:

Would the use of blockquotes confuse some machines that read the site? (And would this be good or bad?)

(He did it again!)