I'd call it passion! But it's like mindcrime said, mostly a case of word inflation in this particular context.

So for me it's not what word I'd use instead of "passionate," but what word they're using "passionate" instead of. The most likely candidates I'd put forth: Naive, positivist, perfectionist, agreeable, friendly, excitable.

I think teams with too many "passionate" (in their use) people run into serious problems.