I'm pretty sure the point of this thread is that it wasn't a 'military grade' design over a weekend, and as GP notes took over four years. It's sort of like saying Microsoft Excel was designed over a weekend.

The problem people have is that designed is a very flexible word that can mean a great many different things, and because of that it's being used here in a way that means something akin to conceptualized, but also used in the title in this way specifically because it will suggest to people that all the design work was finalized in that period.

That's click-baity in that it plays with people expectations, and not in a way they generally enjoy, so they're annoyed. If you don't like click-bait, the appropriate thing to do is to complain or abstain, otherwise you're just reinforcing their decision to communicate in that way.