It would certainly not be ideal for such close distances, but the fact that it's been done in the past, with bigger, heavier, more powerful cartridge/rifle systems, indicates to me it's not a great liability....and how a cartridge/rifle system capable of that is a liability at the 8m range.
Other than Javelin, which is carried in very small numbers (one? two?) by a dismounted infantry squad, what is there?Even among the infantry squad, there are weapons capable of reaching out to 800m, where a rifleman can't even see a target unless he's using optics.
I'd say it's made in recognition of riflemen being the most numerous soldiers on the battlefield.The statements are made as if riflemen are the only soldiers on the battlefield.
It would be interesting to poll riflemen to find out if they would prefer to stick with 5.56 for its CQB superiority, or switch to a somewhat more powerful cartridge like 6.5 Grendel.