A recent user on Kotaku said this:
"The first type of a passionate person is the wonderful one. They are passionate about something and they think that this thing is wonderful. They spend their time on it because it gives them joy. These are the people that contribute (whether they make some sort of a career out of it, or only rudimentary amateur attempts that never go further), or else who consume it incredibly (or both!). They talk to other people about their passion and try to show them why it's so wonderful.
The second type of passionate person is the jerk. They are passionate about something and they think that this makes them unique, and so they jealously guard it. If you don't know about their passion, they regard you as a pariah, some ignorant fool that isn't worth their time or compassion; if you DO know about their passion, but not in the exact same way as them, they shun you as an imposter, or a poser, someone who wishes to steal from them their unique status. These are the people that quibble over minor details as if they are life altering, who correct every teeny misstatement with a pronouncement that begins with "Well, actually..." and who actively drive away others from their passion."