They have a point. The raise the front end of the bike into a more relaxed position AND allows you to get over the bike more instead of riding it (this protects the dangly bits). A racing position is not the best position when riding in 'freeriding' style areas. Risers also tend to be quite a bit wider (thank god) as well the stems are usually 30-40mm shorter all of which makes steering more touchy and reactive imo.
I can only share what I think as I am glad to see flat bars have been left for xc only. I was never confortable before and all I ever did before last year was commute.