I want MPs to earn well, and I want them to have access to reasonable expenses. I don't want to go back to the days when the only people who could afford to be MPs were landed gentry, who did it as a kind of hobby.
And the good MPs do work ridiculous long, long hours under what for me would be totally unacceptable personal scrutiny. It's a horrible job, and I don't understand why people want to do it - but they do.
But still, with adequate expenses and all the other advantages, £67k a year (with more on top if you get a cabinet position) is enough for people who truly wish to go into it for public service reasons.
And the "high earners wouldn't be able to afford a cut in salary" thing doesn't wash with me. People who were high earners before will already have many of the things (education, car, home, etc) that people on smaller incomes struggle to afford at any age. People may want a house with a mortgage that can't be paid by someone earning £67k a year, but nobody needs such a house. And normal families make much bigger sacrifices all the time to help family members eg, retrain or whatever - I also don't buy the "high earners don't want to make their families suffer by living on only £67 a year".
Being an MP isn't some mystical profession that only a few can hope to do well. If some high earners drop out of the running, we aren't going to be left with a dreadful dearth of people who are willing to stand.