Because 'anti price gouging' laws prevent the price going high enough to make it worth someone going to extreme efforts to upscale production.
Without those laws, the price going from $1 per mask to $10 per mask would still be very much affordable for everyone who really needs a mask, and factories who can successfully get decent production underway will earn lots, making it worthwhile to take on the risk of chasing a (possibly short lived) demand.
Without those laws, the price going from $1 per mask to $10 per mask would still be very much affordable for everyone who really needs a mask, and factories who can successfully get decent production underway will earn lots, making it worthwhile to take on the risk of chasing a (possibly short lived) demand.