I personally do not celebrate these holidays but I think everyone has to do what is right in their heart. In other words I think people can celebrate these holidays and it does not bother me at all, but for me and my family it is not the right choice for us because it would bother me too much.
For those interested though, the reason why we choose not to celebrate them is that these holidays combine pagan worship with Christian worship. Most of these holidays were made by combining aspects of both to satisfy people. Easter for example is even named after a pagan goddess that was worshipped named after Nimrod's wife, Semiramis. Many of the pagan aspects date back to Nimrod and the tower of babel. Nimrod was the great-grandson of Noah who rebelled against God and tried to elevate himself to a god. According to history Nimrod's wife Semiramis had a illegitimate son Tamuz who she claimed was Nimrod reborn. When he died she claimed he was eaten by a boar(one reason why historians say pig is eaten to celebrate Easter) but resurrected each spring. The easter bunny is a symbol of fertility that was worshipped and the egg was also a sacred symbol back in Babylon. Festivals began to celebrate ceremonies around the egg and many places began coloring them during the festivals.
The Christian Answers website has a great article on this here http://www.christiananswers.net/q-eden/edn-t020.html
I agree with coloradoperkins that this means that it is a mixture of true worship with false worship and I personally do not think this would please God.