I agree with those who say that paying taxes is more important as tax money funds public goods. I have no idea who came with the hare brained idea to let the most wealthy people offset their charitable giving against their tax bill enabling them to pay very little tax both in relative and absolute terms.
What enrages me even more is that the majority of people don't have any choice. Only the very well off are able to use charities to avoid paying tax. I can't see how this can be in the public interest. If it really was, then the activities of these charities should be funded through general taxation.
However, no doubt a lot of money goes to things which only benefit a smallish group in society. Apparently, Cambridge and Oxford Universities get quite a lot in charitable donations, these are incredibly rich institutions, arguably it would be better if that money ended up with the tax man then the UK's deficit might be a bit lower.
I find it a very unjust approach to taxation and very short sighted as well as in the medium to long term it will not be in the UK's interest, only in the interest of a handful of individuals.