Missed my point completely.
Firstly, if it was tongue in cheek, that didn't come across at all. It seemed, instead, to clearly state that anyone thinking their fingerboard is "ruler" flat must be an ignorant fool.
Secondly, I would never ASSume that. I started playing professionally in the 1980s. I didn't start adjusting my necks for zero relief until I moved to fretless full time (also 1980s). I then learned that for styles where you move all over the neck, as I do, the action is inconsistent if there is relief. Relief is designed ONLY to help avoid string noise when playing in the lowest positions, and actually has counterproductive effects on string action in various ways higher up the neck. Those are facts of science, and I'm absolutely not the only person who plays bass, or guitar, with a flat neck.
Thirdly, obviously. "Pay attention?". If you "pay attention", I specifically was continuing to call by the same name ("fretboard") since everyone here is well aware that a fretboard and fingerboard refer to the same part of the instrument, and the wording stayed more consistent that way. But, speaking as a professional violinist as my primary instrument, I'm well aware that it is a fingerboard, not a fretboard, on a fretless instrument.
Small comment about wording. I was not being insolent. I was pointing out a fact that people can, in fact, use a ruler to ensure their fingerboard is perfectly flat. Since I am an example of someone with zero relief in the necks of my fretlesses, my ERBs, and pretty much all of my basses with probably one or two exceptions for specific reasons, I have come to learn that someone claiming that their fretboard, or yes - even their fingerboard (!?) - is ruler flat, may actually not be an ignorant fool, despite your apparent belief to the contrary.
Lastly, I played an old Fender Precision for several years as my primary bass, and on that instrument played jazz, fusion, rock, RnB, musical theater, Jaco covers, Rush, and (ironically enough) YES covers. That was my instrument for the first 5.5 years of my bass playing life. I'm a huge proponent of good tone coming from good technique, and versatile tone coming from versatile technique, mostly because I come from the most expressive musical instrument ever made - the classical violin. Not sure who you are trying to educate about this, but it was wildly off topic and addressing entirely the wrong person.