Is it because they a good looking? I don't think so. Bullfinches are good looking. So are Goldfinches, but we don't all get click happy with them, do we? Is it down to rarity? To a point, maybe, although they aren't really any rarer than a Common Redpoll this winter. And so far Mealies have been left alone by the camera pointers, haven't they. Maybe they are easy targets because they are relatively tame and sit on top of things? But so do Starlings.
I reckon it's a combination of all the above, plus a primal attraction to things nomadic. They come from the arctic wastes, hang around adding exotica to housing estates, industrial estates and roundabouts and then flee back eastwards when the berries have all gone. Plus, they also have one of the loveliest calls that a bird can make.
Even though I have seen hundreds of Waxwings in the UK, and quite a few in the past month, I still walk the streets looking for them. If I came across a flock tomorrow, I would still trawl the local area again the day after.
I think I might have stumbled upon the real reason that we cannot get enough of them. It's because we have no idea when they might come back and visit us.