By playing so often late into Saturday night 2-3 times a year now

It boils down to you think it is a problem because you believe it is gods will that BYU not play on Sunday.

I don't understand why this does not apply at all times and in every venture the church has ownership in.

I suspect it is because the church wants to use BYU athletics to convey the importance of keeping the sabbath day holy regardless of whether it is consistent in it's own practice.