These are not schemes to avoid taxation because avoiding taxation implies that the donors will benefit materially and that is not the case. It is that governments have decided (rightly) not to tax donations to defined causes. What is happening is that the beneficiaries receive $100 instead of $70 with $30 going to the government.

The givers benefit from the feel good factor but they do not benefit in a material way and it is insulting and mean minded to imply that they do.