Right and it's a matter of opinions. I think bush vipers are the best looking snakes because of the way they remind me of a dragon. I had two but I wanted to solely focus on cobras because I can't work with vipers in the same with I can with cobras. Every cobra I've ever worked with will let you know what kind of mood it's in, a viper you can't really tell and if you get within striking range, you're likely to get bit.
As far as keeping, yes I think may people shouldn't keep because of either lack of being prepared or in some cases they get them for the wrong reasons.