I don't believe so. In KDE3 it was double click IIRC then it changed with the single click during the web mania UI when people suddenly wanted the big unification for everything: phones, fridges, tablets, supercomputers.

Like a lot of other people mention, this is the first thing I flip in plasma too. A mouse with a pointer is just different from a tactile interface.

I personally don't remember it being that way but it's been a long time since I've used KDE. Like, Mandrake was still a thing when I last used it.

Partially, sure, but there's also a lot of KDE devs that are really convinced that it's objectively superior and wanted the default to convince more people to use it.

In 2004, Microsoft was granted a patent on using a double-click on "limited resource computing devices". As a result of this, some observers fear that any U.S. company which uses double-clicking may have to change their product not to use the technology, pay licensing fees to Microsoft, or give Microsoft access to intellectual property.