IMHO (I am probably wrong), contribution of a company is not and should not be measured by ONLY one standard (corporation tax) but a balanced score card approach should be adopted, namely how much "other tax" is Google and others major firms paying? are all the staff paying the right amount of PAYE and other tax? do the Corporations contribute in money and in kind and make a measurable impact to the local/national society?? by all means lets get the real life data/measurements and compare that with the local council (government) vs other national firms, and multinationals??
Indeed, it is not a good excuse for firms not to pay tax, but this is indeed an endemic problem of the capital market, which is highlighted very well by the brilliant book of Prof. Colin Mayers's Firm Commitment.
Talk and accusation by popular culture (press/committee judge & jury) is cheap, "real actions", measurable results and lasting impact speak for itself, no!? Lets find out the real problem and devise a viable solution.
Please forgive my probably flawed & grammatically wrong post but I hope the central idea was conveyed.