Personally, I think that it can be justified in picking Jones ahead of Read if the additional runs he scores with the bat outweigh the runs he concedes behind the stumps. No wikcetkeeper should drop catches, and Jones isn't bad enough for his catching to be considered poor, I don't think.
Given that Jones, in Tests at least, is by miles the better batsman (in my opinion) and averages about 40, Read averaging around 20 off the top of my head, I think England are justified in picking Jones, because it's unlikely he would concede on average 20 more byes per innings than Read, which he would have to do to cancel out the extra runs he scores. By picking Jones, England have a "net run gain" on average.
I'm staying out of the ODI argument, because I am always guilty of favouritism when it comes to players, so the fact that I believe Jones should play counts for nothing.