A Not Very Approachable Professor I am in a math PhD program, and I feel that my long interest in a particular area of mathematics is discouraged here. 

I have an interest in an area of mathematics, but the leading person doing the research at the institution which I am going for PhD is not very approachable. I went to office hours for one of the classes I am taking and this person (to me) seemed very stand-offish and was ready to let me go out the door for a simple question regarding the class material. The professor was also very critical of my background and where I got my previous degrees/experiences at after a brief conversation. Thus, the experiences with said individual lead me to feel discouraged and potentially lead me away from my interest in said specialization within math, as they are the leading faculty in this institution doing the type of research I am interested in. 

What should I do in this case? Should I just accept things how they are and try a different approach, or is it even worthwhile to try to transfer somewhere else?
Another late answer. 

In undergrad, there is a maxim that you should "choose your professors as carefully as your classes." I think in hindsight, most graduates agree with this -- we've all had random classes taught by great professors that were meaningful, while great subjects taught by lousy professors were worthless.

How much more crucial, then, is the choice of your PhD advisor! An advisor in the right area but with the wrong personality is a terrible choice. An advisor in a merely acceptable subfield but the right personality is a much better choice. 

Ideally, you will (a) find someone at your current school who will make a good advisor even if their research area isn't obviously aligned with your current interests, or (b) find that the professor in question is actually reasonable once you get to know him/her. But, I think transferring out would be preferable to working for an unreasonable person -- I've known multiple people who stayed in grad school for 10+ years, and the common problem was an unreasonable advisor.