So since this seems like it would be dead simple to add, and the desire for it is clearly there among many users... There must be some downside to adding it th

So since this seems like it would be dead simple to add, and the desire for it is clearly there among many users... There must be some downside to adding it that I'm missing. Outside of some potential for people with domains to use it for humor, or for tracking in some way, I can't see much. Anyone else got any idea why not?