I think it’s a mixed bag. I’ve been insta-buddied with some real dorks. I’m sure there are some dives where I was the real dork, too.
I think
@nolatom gives great advice about arriving early. That gives the DM time to assess skills, go through some basic matchmaking and provides time to both parties to get to know each other. The more seasoned diver can proffer some pointers to the new diver and the new diver has time to absorb new information.
When buddies are assigned at the last second is when both parties feel burdened. The experienced diver feels like his dive profile just got compromised with an unknown variable that will require baby-sitting and the new diver, full of cheer and excitement, now feels like he is just that, a burden.
I think experienced DMs get in front of that stuff early to prevent disappointment. I think being a DM should be very personal with lots of eye contact, listening and pro-active problem-solving.