For me it's the fact that on the playlist one, a third of the nodes are already not interesting because they are gambit, and then there are the pvp ones that require kills by ignition, jolt, suppression, and these tedious things... Also, you might be enjoying your strikes and then being hindered in progress by having to change from your enjoyable strikes to gambit or crucible in order to progress. It just is more of a hassle to navigate through the pathfinder for playlist than the pale heart one. Perhaps the solution is a pathfinder for each of the three playlists, so you'd have more paths available per activity.