Most of them do not say they want to scrap the BBC, but they do say they want to end public funding such as by scrapping the license fee.
If that is the case, then the BBC will likely become subject to the same kinds of incentives as other large media organizations, pleasing advertisers or audiences etc...
I would rather that they continue to be publicly funded and continue to annoy people on various sides of the political spectrum instead of pandering to them like the garbage that passes for "news" on cable channels, or going the Piers Morgan/Julia Hartley-Brewer route of shovelling spicy debates to people who want to be entertained.