"when no one need be judged by the quality of their script"

The reviewer mentions Thomas Aquinas, whose writing was notoriously illegible. She might have mentioned Napoleon as well, or quoted from Middlemarch

"At that time the opinion existed that it was beneath a gentleman to write legibly, or with a hand in the least suitable to a clerk. Fred wrote the lines demanded in a hand as gentlemanly as that of any viscount or bishop of the day: the vowels were all alike and the consonants only distinguishable as turning up or down, the strokes had a blotted solidity and the letters disdained to keep the line--in short, it was a manuscript of that venerable kind easy to interpret when you know beforehand what the writer means."