I look at it differently. I don’t think it reflects a preference for mashing words together – instead it is a convention that encourages you to consider how you name identifiers in your code, and, more generally, how you organize the concepts you’re working with.
Strive to choose concise names, not too short, not too long. If you need underscores, it most likely means that you can work harder to find a better name, or perhaps that you are mixing together two concepts that should be separated.
It reminds me about the principle (which has been mentioned many times) of implementing as much of the Julia language in Julia itself, even when dropping down to C or something else would be easier and more efficient. It sounds like a potential handicap, Julia could be faster with more C code in it, but in the long run it’s better. Analogously, discouraging underscores forces you to work harder and do better.
I think that if you stick to the convention, and put in the extra work, your code will in the end be more readable.