Some businesses will not serve you if you aren't wearing shoes or 
shirts.  Some businesses will not serve you if you are drunk or 
disorderly.  Some businesses will not serve you if you do not look like 
you fit their customer profile.
Go into an Apple store with the 
wrong look, educational level, or attitude and you will be discriminated
 against or treated differently.
Go to a Democratic Party meeting,
 announce that you are Pro-Life, and I guarantee that you will be 
discriminated against and probably will be physically roughed up.
Discrimination
 happens every day and probably those who are worse discriminators are 
those who profess to be against it.  We, even ABC reporters, all 
discriminate whether we recognize that we do or not.
How does a 
store clerk make a decision whether someone is gay or not then 
discriminate against them?  If you can't tell whether a coworker or 
friend is gay how could you tell whether someone walking in off the 
street was?
There are people in our society who want to force 
others (using government power) to be uncomfortable.  They want to force
 a person whose religious beliefs are different from their own to do 
things that the person would be uncomfortable doing.  Catering a gay 
wedding would be uncomfortable for some people.  There are plenty of 
caterers who would love the business.  If I were gay and getting married
 the last person I would want catering my wedding would be someone who 
was uncomfortable doing it unless I was a really big AH.  Like, what is 
really in those petite fours?  I would be honest and try to work it out 
with the caterer or get someone different.  Easy.  Offended?  Nah.  
People are different.