Diver Dennis:
Damselfish, where did I say "you can't have a buddy" or "had to ignore them" or "swim on the other side of the ocean"? I did a private live aboard in Palau, the Eclipse but also dove with Sam's who did this. I dove in Yap at Manta Ray Bay, same thing. Same in Mexico but I solo there a lot. In the Philippines I'm mostly solo but when with a group, they stay together and frown on people who don't.
Most dive operations want you to dive together with the group unless you've been there and know the area. Where do you dive where they just let you go off on your own?
I guess there is a little confusion at this point (at least on my part) on what "this" is.
My profile says where I've dove. Maybe I pick the right ops. But, I did dive with Manta Ray Bay, and I don't remember them saying anything about people staying with the group. They tended not to say much of anything, actually. Now, if you're going to a cleaning station to wait for Mantas, and presumably the local DMs know better where the Mantas will be, doing otherwise doesn't make sense and it really doesn't come up. ("I think I'll just go swim over that bare sand plain with lousy viz instead of seeing the Mantas.") But we did other dives with them too and I don't recall any big hangup about it. I imagine they would have a problem with it if someone did something actually stupid, but that's a different matter.
Now, if you drop a group of people off a boat onto a wall, it doesn't make much sense to swim way out to sea, or towards shore until maybe later in the dive, that pretty much leaves 2 choices (aside from depth.) One choice, if there's a current or some special feature on the site you want to see which is common. In this case you may wind up with a sort of group by default, but that's not the same as herding, and people don't have to be on top of each other.
I'd say the majority of my boat dives, they ask who wants to tag along with the DM and who is doing their own thing, just so they know how many/who they are keeping track of. Typically DM heads one way, half go along, other people head opposite or all over the place. Yes I've been on some where they insist on follow the leader (for no good reason IMO) and no I don't like that either and try to avoid it. Now if they tell me they're going East, and we shouldn't go someplace else because there is nothing to see or I will get sucked out to sea by a current, I am happy to listen - that's the sort of useful guidance I am paying them for. Most of the herders I've run into do it on deep sites when they're paranoid some people will go too deep. Anyplace where there's a big area with coral fingers and patch reefs (and lots more potential to get lost) I don't think I've ever been made to follow a group. Typically they draw a map or give a description and declare pool open. There's often suggestions on what might be a good general plan to hit the most good stuff, but people spread out and often you rarely see people until near the end of the dive.