Back in my day we HAD to headspace and time the m2. These kids these days are lucky with m2A1 with the fixed head space...I cut my teeth on a 1911 and M14. The guys before me thought the 14 was garbage. Nothing could replace the M1. Yet many operators still use versions of the 14 for sniper duty.
I thought the M16 was garbage and no way I was going into combat with a .223 squirrel gone. 40 years later....
So, I guess each generation has its tools and the previous generation will always bemoan the changes.