Because it's explaining the wrong confusion. People who are confused about pointers and arrays in C don't think that the concept of a pointer is the same as the concept of an array - they think that in C, the two have the same semantics. That explanation and analogy do nothing to explain the semantic difference, and honestly come off as a pretty condescending by essentially saying "Well they're different things, of course they're different!"

The poster probably did not help matters after that by calling the downvoters "clueless n00bs" or making a self-righteous statement about how they won't delete the comment just because of downvotes. That kind of toxic behavior just ensures that you'll get more downvotes.