Easter traditions like eggs and hot cross buns also make everything a bit more confusing...but I always think of Jesus when eating a delicious hot cross bun with plenty of butter.
Many traditions start out as illustrations that are meaningful. Easter eggs were to symbolize rebirth & the empty tomb. Nope, I don't really get it either, but if it helps someone else understand, praise God for it.
Christmas trees are evergreens and look living through the winter as a sign of hope when all seems cold. The lights (originally candles) represent the light of Christ. We give presents because the magi brought presents to our Lord. The same with birthday presents.
The thing is, we love our little ones, and will go to great lengths to make these holidays fun and enjoyable for them, knowing that they are unable to perceive much of the meaning behind the fun.
There are many things that we blame on the enemy that I believe we need to look to ourselves, but I think that the removal of the meaning behind many traditions has the fingerprints of the adversary. I think he strengthens anything that displaces thoughts of the Lord, and works to subvert anything that draw us to Him.