They's all kin to the cannon clan - old'uns, young'uns, we'uns and yer'uns!
In regards to the .50 MG detractors, it's fairly obvious that the AN/M2 made it's presence felt across all theaters against Axis types.
In reading pilot biographies (Axis and Allied) over the years as well as viewing guncam footage, very few Axis targets managed to get away intact after receiving one or more vollies from the .50 MGS (regardless of the combination).
I'm not sure why there is such a push to downplay the fifty's contribution to the war effort and I certainly don't see how supporting the .50's historical performance is "flag waving" when other nations used that caliber as well.