What would I call this 'attitude'?
Solution 1:
The closest I can think of is dismissive. To be dismissive of someone or a group of people is to refuse to give proper consideration to their merits. Having said that, this seems to lack the venom of your example.
http://www.merriam-webster.com/dictionary/dismissive
Solution 2:
Some words you might use are judgmental, petty, or spiteful.