Maybe we're at the point where it doesn't matter, because at 25 mb there's plenty of resolution for the largest print size that FAA offers. I just sold one at 36" x 28" taken by a 10 MP camera and if the buyer is happy, and FAA's printer is satisfied, then I'm happy too and maybe we don't need to waste more time and bandwidth uploading monster files. Downsizing a photo, within sensible limits, is a good way to clean up noise anyway.
It only needs to be as good as it needs to be for the printing technology.
But guys who do things like finely detailed landscapes, with big sensors and top drawer lenses, may have some cause for dissatisfaction. I get that.