My theory is that the prevalence of blue LEDs to this date is an after-effect of people who grew up back when blue LEDs were rare and expensive, and who came to see blue LEDs as a way of signalling higher value and who got used to wanting to put blue LEDs in everything for that reason long after the signalling effect was lost.

(it was first in the early 90's that bright blue LEDs became available, at least at reasonable price points)

I suspect there's a lot of truth in this.

This reminds me of going for an interview at Durham University in the early 80s. A professor in the physics department proudly showed me a prototype blue LED that they had developed. It was indeed quite a novelty at that time.

Ah, yes - a quick search confirms there was research in this area going on at the time: https://iopscience.iop.org/article/10.1088/0022-3727/16/6/02...

Undoubtedly I agree with both of you. Unfortunately, since the introduction of blue LEDs little thought has been given to the way people react to them. From my experience, they seem to raise the most criticism of all colored indicators.

I have an air filter with the same similarly bright blue LEDs. But, it has a night mode which you specifically have to enable each time where those are turned off. So the people who designed this thought of this problem and still wanted to have the overly-bright LEDs with no function. I don't quite understand.

Ha, I used to have a shirt draped around the neck of the fan for this exact reason. Didn't work too well, some of the light still bled through