Calm down, no reason to yell.
You should do a little research. Yes, a restaurant can refuse service for improper clothing, poor hygeine or for being a disturbance, no one is arguing that.

What a business owner can not do is refuse service based on sexual orientation. That would be against Colorado law.
The baker does not have the right to discriminate based on anything, his religion, or the Constitution. The Constitution does not have anything in i that says you can discriminate based on religion.

The baker is immature and choosing to be offended.
How will he know in the future is he is making a cake for a gay wedding?
What if the mother of a bride goes into the shop and asks for a wedding cake? Is the baker going to ask the mother if the cake is for a gay wedding? He has to be told the cake is for,a gay wedding. Then he chooses to be offended. 
If he does not know, he will make the cake and not be offended. 
I bet he has made cakes for gay weddings and did not know it.