In most cases of high net worth individuals they are not giving money directly to public charities.
They are giving money to personal charitable trusts owned by themselves which they then use to buy influence in society which benefits their business activities. It may not be a direct benefit, but its a significant one.
There is a strong tradition of wealthy individuals backing each other’s pet charitable projects as part of their regular business processes. I don’t think we should be surprised that the Government wants to take this out of the scope of tax relief. Philanthropy should be about supporting things the person believes in rather than what might be prudent tax or business wise.