Sounds like he wanted you to just show up, be impressed by what you saw and sign up on the spot. Crossfit is obviously a weird fitness cult but they do have the awesome marketability of "look at how bad ass and sexy we are, come join us and be a sexy bad ass too" which only really works on a visual scale. Verbally explaining what crossfit is makes you sound (rightfully so) weirdly fanatical which probably wasn't that effective as the visual marketing aspect.

He could've just been a normal bloke that liked an intense work out as well, maybe that's how he got introduced to it too. But I can see how sexy, vague and mysterious marketing would have worked to draw people in.