I'm no apologist for MLS, but can see where he's coming from. Whilst it is a generalisation, I find it quite rare to see gash flying or engineering from somebody whose paperwork is neat and systematic. Similarly, I've learned through experience that if somebody's paperwork is gash, incomplete or inconsistent it's not unusual to find that some other aspect of their work is too.
But, it is still a generalisation - Whirly's logbook may well be very scruffy but I know her to be a very cautious and safe pilot; similarly I can think of one or two people who have produced beautifully neat and tidy paperwork, and some very dodgy aviation!
However, we should take every clue available to us, and I'd defend MLS's view that he should take a slightly deeper look at somebody who can't keep their logbook neat and tidy.
G