Maybe because that's what she is knowledgable in, and she wants to point out bad practices in the industry she's involved in, or because they make expensive houses with cheap products that are only built to resell as opposed to have someone actually live there for an extended period of time?

Look, these things might not mean anything to you (or me for that matter), or ever have a real effect on you and that's fine, but you really can't imagine why such poor practices might annoy someone whose career is based around knowing not to do these things that are so prevalent?

Do you think subreddits like /r/programminghorror are mean spirited? If someone posted a snippet with 1000 cases in a switch statement, would you say "Why should anyone care what sort of sort of code people choose to write or use in production?"

I don't see how that is any different than this, or how calling out bad practices with broad strokes is a mean thing to do.