Pretend the initial comment didn't say LAMP but just said "web app". That's clearly not useless, right? You can tell from context that it must be software, but "web app" is an obvious improvement from there.
You could argue that "LAMP (Linux, Apache, MySQL, PHP) application" instead of "web app" adds nothing more than "web app", and I won't fight you on that.
But surely it's still at least as good as "web app"!
Also "that vague description" was referring to "cage with an engine and wheels". It's crazy to say that's a useless description, when the starting point is "anything in the world".