Hinders. What you're trying to find is someone who's got similar goals/ambitions for how they want to live their life in future, and who has a good sized surface area overlap with you on how to spend their free time now.

Dating someone in the same field gives greater likelihood of finding that, but there's other ways to do it too. People who went to similar schools, people in related fields, people who hang out at similar social events...

Your work is one field where you can find overlap, but there's lots of others. My fiancé works in a completely different field, but we have similar preferences in how we spend our spare time. I'd have never met her if I restricted myself to programmers (she's in conservation and events; an odd mix to say the least).