A Modest Thought

[Zojha]

Different pathways would not work too well IMO, it would just cause more bickering.

It definitely would - And to curb that bickering, you'd put up multiple copy&paste versions of the same dungeon into the DF that simply only allow one of the given paths and people can then queue for that path directly. If the paths are mutually exclusive, there is no functional difference between the two concepts except that people agree on the desired path before queuing up.

And then people leave if they get path X in roulette >_>

Without DF, people form the party themselves and generally agree on a path/goal before getting into the dungeon. If someone wanted to do an Emperor run in blackrock depths and you didn't want that, you simply didn't join the group. With DF, you no longer talk about the goal before you zoom into the instance, hence you need a way to agree beforehand what the goal of the run is. And the easiest way to facilitate that is to simply put only one goal/path in. And even THAT still causes in-group friction because some people want to reach the goal faster than others >_>