They picked wrong.
They should have picked Standard Time.
They should have picked Standard Time.
Ultimately, it's entirely arbitrary anyway. The only issue is that American states cannot pick DST without a federal law change.
This 65% started during the Dubya presidency (source: I was there updating tzdata on systems), and previous to that it was a 50/50 split.
So 65/35 or 50/50 is arbitrary.
Obviously all this is arbitrary including standard time.
There was no reasoning for the Dubya alteration: the change was not debated anywhere, and (AIUI) no one was ever able to figure out how it actually got slipped into the legislation.