Hah. This is the opposite of every single experience I've seen at my work, where both PCs and Macs are supported. Usually the Mac person plugs into a projector and it doesn't work, or they don't have their adapter. The HP works every time.
Well if they don't have their adapter that's not really a problem with the Mac's compatibility now, is it? They simply forgot a very important piece that will help them achieve the goal. I don't blame my TV for not getting a signal from my PC if I lose my HDMI cable.
I know my experience is anecdotal. So is yours. Just shared what I've observed 30+ times now.