The whole point of my post is to try to get all of the resolution that is possible from the shot when you can. I might have a great shot that is nearly full frame of a player shooting a ball while in the air. Later, I might want the large photo to be the entire player showing them two feet up in the air from the floor. In that case a slower shutter speed may be fine. Or I might also have a great facial expression and I want to take a 30% crop - and here I want all the resoultion that is available to maximize my options. So what I want when I'm shooting is to not limit what I can do with the photo later because I threw away resolution due to motion blur. I want to get the most resoultion I can get ... only limited by my equipment. So a 1:1 post is inline with that objective.
In fact, even if you only wanted an 8x10, the amount you can crop to make that 8x10 may be limited by motion blur if you did not optimize for that parameter.
I'm also not saying that it is wrong to optimize for some other situation or purpose. There is no right or wrong here. But if you want to optimize for available resolution, then you need to carefully consider pixel density and shutter speed.