I think what Ashton is trying to convey is that it doesn't make sense to over-generalize and say that rationalism = conscientious, up-tightness and irrationalism = laziness, flexibility. Doing that is the same thing labelling people like saying every ENTp is the same or every ENFp is goofy. I agree with him on this matter. Of course, rationals are more likely to be organized and irrationals are more likely to have low self control, however it doesn't necessarily indicate that is accurate for every rational and irrational.