Bus Hoppers

I noticed something peculiar today. In fact, I've now noticed it 3 times in the past week. While on my daily commute up/down Connecticut Ave I witnessed a hopping. Has anyone else noticed these? It's like a transfer, except it's not. Instead of boarding a bus headed in a different direction or with a different destination, these hoppers wait for a stop to come then get off one bus only to board one that's on the same route. I've noticed it only really happens during rush hour, when buses tend to 'stack up' one in front of the other on the road.

Last week I witnessed someone get off my bus, run behind it to get on the bus behind me which was running the identical route, only to see him get back on my bus a few stops later!

While I suppose there's nothing intrinsically wrong with these hoppers swinging from bus to bus, I just don't understand why. The destination isn't changing. The traffic isn't changing either, so it can't be any faster. The only explanation I can see is the atmosphere mustn't be good enough for them on Bus A, so they try their luck on Bus B. I'll admit that sometimes the Metro buses stink a bit, or the clientele is unfortunate (and certainly rude) but does this really warrant all the effort to change buses?

I'm puzzled about these hoppers. Maybe I'm just lazy. Or then, maybe I'm witnessing the newest fad in urban exercise. Can anyone explain this? Are there any hoppers out there?