Hey, why do you bother when a church establishment which you do not believe in, makes one of its dead members Saint with pomp and publicity ? Since it does not involve you, why make a fuss out of it ?
This is a question many atheists faced in connection with the canonization of Mother Teresa.
There are several reasons why it bothers me and other atheists. The Vatican is not just issuing a sainthood certificate. To make a guy or gal Saint, the Pope should be convinced that they have done two miracles on this earth after their death. It is thus openly questioning science and scientific methods by proclaiming the alleged miracles to be true. Thus the Catholic Church is wilfully indulging in spreading superstitions. It is misleading people and make them turn away from science and scientific methods.
Miracles, according the Church, are supposed to be happenings that do not have any credible scientific explanations. Let us for a moment concede that the alleged miracles has really no scientific explanation at present. Does that mean the Saints did it from heaven? Or does it mean Science has yet to find a good reason for it ? Science has found credible explanations for many things that were considered miracles thousand years ago. So will the Church take away the Sainthood when the “miracle” get a scientific explanation ?