They are an integral part of BJ's style and represent an added opportunity for the band (and of course Richie!) to express their true talents as musicians. A song without a solo wouldn't be Bon Jovi IMO and would be an inexplicable and blatant waste of a true guitar talent that so many new musicians are lacking these days and is only present in the lucky few!

As for other bands, the same goes. If they make up the usual, successful structure a band adopts, then it would be a crime to throw them out.