But Kelly, by much of the country do you mean the majority? This thread (as a possibly unrepresentative sample) I would say has tilted more in the diretion of either "good for them" or " I don't care either way", rather than an intense dislike of Camilla.
I don't suppose we'll ever know whether he only saw Diana as a brood mare, or whether he was determined to continue the affair with Camilla from day 1 - we just won't know.
FWIW I think it's possible that given his position he succumbed to pressure to marry someone of a higher rank than Camilla. The marriage to Diana smacks of an arranged marriage, which may not have been wholly within his control, and if so it's not surprising that it didn't work out - but not necessarily the sole fault of Charles if the marriage was pushed on him.
(Whether or not the royal family adequately serve in return for their position is probably for another thread, but I do think it would be unfair to say that the key members of the RF do not do a lot.)