"do I buy into the crassness and commerciality once again or just take the basic Bah Humbug tack and do my best to avoid it all?"

There's another option, you know. You could do whatever pleases you personally. If making the beautiful Christmas music pleases you, then can. If giving to good causes or feeding the hungry gratifies you, then you can. If calling long-lost relatives and friends means something to you, go ahead and wish them a Merry Christmas.

If you don't want to shop, then don't. If you don't like tinsel, don't use it.

It's your life. Take control of it. You don't have to choose between being a consumer and being a humbug.