Yes, but that is not the same as telling competent professionals to exercise more care. Accidents are prevented by creating systems that make accidents hard, not by requiring more vigilance from individuals. This is why bandsaws come with guards and other safety features.
Someone who can't figure out how to use CSS effectively in about an hour is not a "professional". CSS is very simple, and very powerful. People's underdstanding of it seems to be lacking, and it almost seems like from these comments that it comes down to willful ignorance.