That’s a pretty silly stance. If I tell you not to touch a hot stove do you expect me to give you instructions on what to touch instead? And if I don’t are you going to burn your hand to spite me? “Well if you don’t have a better idea I’m just going to keep burning my hand”
Well if you need to do X, then yes, you need an alternative. The alternative of not doing anything is worse in the case (or at least that premise seems to be accepted by the author). So if you say do X but don't use tool Y, then you need the alternative.
Your stove metaphor breaks because the alternative of doing nothing have no consequences.
Advice on what not to do IS an insight. And there's an argument for why not. The idea that you have to give an alternative in order to not be "negative" or whatever when there's not a one-size-fits-all piece of prescriptive advice is just dumb.
