Perhaps this is harshly judgmental, but in my heart, I cannot consider anyone a true Cal fan if they would not attend just because they are required to wear a cloth face covering. Being a Cal fan isn't, and has NEVER BEEN about comfort.
What's worse, wearing a cloth mask, or sitting in the horrific downpour against the Ducks on November 1, 2008? While it is not my preference to wear a lot of stuff both for warmth and to be waterproof, and even then, it isn't pleasant to be sitting outside while buckets of water are pouring down from the sky, I'll do it, because I'm a Cal fan.
You know people are true Cal fans if they were in Memorial Stadium at the final gun of the 2001 USC game. Better yet, if they were NOT under the press box overhang. Cal was getting blown out, that wasn't pleasant by itself, and there was a somewhat unexpected rain (not NEARLY as hard as the 2008 Ducks game, but people were not as prepared for rain). Yeah, there were only about 200 Cal fans in the stadium at the final gun (about 1,000 SC fans), and only about 75 Cal fans in the stadium who were not under the over hang. Given a choice between pleasant weather wearing a cloth mask or sitting in the conditions that day, I'd take a mask in a heartbeat.
Plenty of people wore masks to the 2017 Friday night game against WSU. I wore an N95 mask with a one way valve (not an acceptable COVID mask). There was controversy over the playing of the game, but since it was played, I wasn't going to let some smoke keep me away, but I preferred to protect my health and wear a mask (although I did take it off on occasion, breathing in the smoke for hours was an issue, not breathing in for a few seconds). The mask was well worth it to protect me from the smoke AND get to witness the blowout of WSU (and the Bowers flip into the end zone). My eyes stung for awhile in the aftermath of that game, but it was WORTH IT. Because I'm a CAL FAN.
I've been to plenty of games at Memorial that were quite unpleasant due to heat, sitting in the sun on the east side. For people sitting in certain parts of Memorial, the 2006 Big Game was extremely unpleasant due to the cold and wind. It was very hard to be bundled up well enough to protect from being cold that day if you were in the northwest corner of the stadium. It wasn't great in other parts, but man, it was extremely unpleasant in the northwest corner (fortunately, I only visited friends sitting there to experience it, I had seats in the sun on the east side that had better wind protection). If I had been sitting there for the whole game and had a cloth mask, I would have worn one to keep my face a little warmer.
If you're the type who doesn't care about the Bears enough to go on a very rainy day, an extremely cold windy day, a smoky day, or a scorching hot day, well, then, I understand why you might stay home if you have to wear a mask. But if you are a die hard Cal fan, then none of that should stop you from going to the game, barring health conditions that make it not just a matter of comfort, but a matter of meaningful health risk. And if those things don't stop you, well, a cloth mask is less unpleasant than those things, and a little discomfort from a mask shouldn't stop you from going to the game.
I hope there is no mask requirement in 2021. All else equal, I would prefer not to wear one, but if the accurately forecasted downpour of 11/1/2008 didn't stop me from going, if the 2017 smoke didn't stop me, if the combination of the blowout and the unexpected rain of 2001 USC didn't get me to leave early, there is NO WAY a silly cloth mask requirement will stop me from going to support the Bears. I don't want a 2021 mask requirement , but it would be FAR preferable to 2020, when we couldn't come at all.