Although there's also a reason why bodybuilders have traditionally thought in terms of "bulk and cut" too, rather than focusing on lean gains. They may or may not be related.
For someone like, say, Alpha, a traditional BB split doesn't seem to fit into his schedule, nor does it seem like a traditional "bulk and cut" would work in his line of work. However, he's successfully achieved "big, strong, and lean" as far as I can tell. Not a bodybuilder, powerlifter, or strongman... but definitely big and strong and pretty lean. I'm basing this entirely on what I've read so far in Alpha's Work 2, so I could be misinterpreting.
For those in a split, specializing in a bodypart often seems to come down to "hit the target muscle more frequently".
In this case, it actually sounds like frequency is more important than "destroying the muscle".
I'm reading through John McCallum's Keys to Progress right now, and what I see is pretty much to destroy the whole body regularly, push the cardiorespiratory system, work to failure or near failure on every set, and take as much rest as you need. He routinely says "if you don't need a 10 minute break after the squats, you're not working hard enough."
His routines seem to be both high-frequency and high-fatigue.
But McCallum wrote for Hoffman, and a lot of split-based training was written for Weider. Weider was definitely the more aggressive businessman, so more people were reading Weider's stuff than Hoffman's. I'm wondering if that had something to do with the popularity of split-based training today as compared to whole-body training.