That's what they choose as their basis.
The older generations choose their warrior classes to be based on "more normal" folk. The mythical, religious, and legendary heroes were equal to monster manual entries. The best you got in specialiness was Aragorn as the "Special Bloodline of Kings" by rolling crazy stats.
The newer generation had no qualms with their PCs being all "super special oddities with special power" from day one.
Basically, you could not be Hercules at an old school table unless you rolls crazy high and the DM is making an excuse for why your fighter has 18 Str, 16 Dex and 17 Con at level 1.
At a new school table, playing Hercules is the norm.
At the mid school table, it's "well Zeus did get with a lot of ladies."
So for "Your Strength and Mastery is Herculean. Even when you miss it hurts or requires great effort to dodge" to be allowed, you have be allowed to be Hercules, Skanda, or Thor.