I think the 1/4" seam became the standard due to less bulk in the seams and at the joining of the blocks.
I know that 4 seams coming together with 1/4" inch seams can be bulky, could you imagine on star blocks and compass and fans...oh my :shock:
I couldn't imagine hand quilting those puppies with a 1/2" seam...
Took me along time to get used to the scant seam.
K