I didn't say anything about their development abilities, what I am pointing to is their professional responsibility. If a doctor is asked by a client to cut off their arm and they say no, and the client fires them, did the doctor err? (No) This doesn't comment on their ability to do surgery.
So just to check, instead of doing something you were told to, that you know is a stupid idea (after telling all concerned it's a dumb idea and being told to go ahead anyway, eg adding a crapton of video to a page), you would just resign, to protect your personal integrity?
no, you offer a technical solution to the problem. Show some videos is the problem. Downloading almost a GB of video content on page load is the (bad) technical solution. There are better ways and as a developer it's part of your job to solve things in a way that makes sense.