My Honda dealer sorted out a new dipstick for free.
They didn't bother to put it through as a warranty claim as they knew Honda would reject the claim.
I suppose a lot more people would have moaned if Honda hadn't fitted one.
You could be right there.
Another thought is there is a key difference between maintaining the correct level in say the oil sump and the washer reservoir. If the oil sump ran dry or was overfilled, it is detrimental to the engine.
But for majority of owners, if the windscreen washer reservoir ran dry, all they'd have to do is refill the reservoir later at their leisure. I noticed the garage virtually brimmed the reservoir when they serviced my car yesterday, perhaps to highlight the fact to me the dipstick serves no useful purpose whatsoever.....