He has addressed this in the past ... apparently this motif is the only thing that works in the youtube environment/interface and other more sensible, or reason

He has addressed this in the past ... apparently this motif is the only thing that works in the youtube environment/interface and other more sensible, or reasonable video thumbnails produce orders of magnitude less engagement. I, also, strongly dislike this (thumbnail) presentation but I suspect it must be necessary as it is very widely adopted.