Meaning - 'out of all proportion to the ambiguity'

Question

The bolded in the last para about the fewer v less dispute confuses me:

The Cambridge Guide to English Usage notes that the "pressure to substitute fewer for less seems to have developed out of all proportion to the ambiguity it may provide in noun phrases like[:] less promising results". It describes conformance with this pressure as a shibboleth and the choice "between the more formal fewer and the more spontaneous less" as a stylistic choice.[7]

What's the meaning of out of all proportion [ie: wholly disproportionate] to the ambiguity? What ambiguity is there? Why substitute one for the other if it still provide[s] ambiguity?

Answer 1

They're commenting on a long-standing argument about proper usage of "fewer" and "less".

There are a lot of contexts where "fewer" is technically correct, but where a lot of native English speakers use "less". ("I have less books than you do" is technically incorrect; it should technically be "I have fewer books than you do". But lots of people do use "less" there.)

"Ambiguity" here refers to confusion created by someone using the "wrong" word (i.e. using "less" where they should technically use "fewer").

The ambiguity created by less vs. fewer is very small. If you use "less" when you technically should use "fewer", 99% of the time people will still understand you, and 95% of the time they won't even notice that you got it wrong.

Because the ambiguity is small, it doesn't really justify people getting all upset about it. By saying the pressure (to use "fewer" instead of "less") is "out of all proportion" to the ambiguity, the writer is saying that someone is getting all upset about it, when they really shouldn't be.