That's an interesting point you are making there. The most common exploits are of the human variety. Even so it is probably a good idea to minimize the chances of all kinds of exploits. One other problem - pet peeve of mine - is that instead of giving people just security updates manufacturers will happily include a whole bunch of new and 'exciting' stuff in their updates that in turn will (1) introduce new security issues and (2) will inevitably try to extract more money from the updaters. This is extremely counterproductive.