By Andrew Holleran Las Vegas Raiders owner Mark Davis has a theory on why his franchise had a high no-show rate for games during the 2021 NFL season. Davis believes his team had a high no-show rate among fans due to the vaccination requirement. “Las Vegas Raiders owner Mark Davis said his COVID-19 vaccination requirement for fans to attend Raiders home games was the primary reason why there were so many people who bought tickets to games at Allegiant Stadium but did not attend those events, creating a high no-show rate,” LV Sports Biz reports. Hey, at least he was honest. “I believe the Covid …