It's basically proven that transmission of the disease is extremely difficult in an outdoor environment. Countries all over Europe have had spectators at ourdoor sporting events, didn't Dortmund have 12k in their stadium just last weekend?
Look at the hundreds of thousands of people who protested during the height of the pandemic for the BLM Movement as well. There was no increase in positive cases due to this.
The Scottish Football Authorities believe it's politically driven rather than scientific driven (the decision not to let football fans in).
Let us see the science / data that backs up that it is unsafe to let small crowds in to watch sport in a safe, outdoor environment.