I think people far too often conflate "I am not interested in X" and "there is no reason to be interested in X". This happens a *lot* with women in the public eye.
There's no reason to minimize Pippa's accomplishments; she has done a lot of good with her platform. In fact, I strongly suspect that if you took a random sampling of 10 people from the various royal forums and put together their lifetime fundraising, 9 times out of 10 you would not equal the amount of money that she's raised so far in the few years she's been in the spotlight. (There's a possibility that 1 time out of 10, you'd find the outlier who's raised a million pounds/dollars.)
As for the wedding: it was clumsy on KP's part and they seem to not yet recognise that any clumsiness in their execution will be pounced on by a fairly hostile press. (Or maybe they do and they just figure they really can't do right so they'll just do what seems best and let the chips fall where they may.) But, really, given that the press is so eager to photograph these "unimportant" people that they spend a day whining on Twitter that they're not being given unrestricted access, what else are Pippa, James, and their families supposed to do? Is there a good way to handle this, or are they going to get criticism no matter what they do?