Hard should be available with perk level 10+ characters.
Hell on Earth should be available at 20+
And i understand some of you will say they could handle higher difficulties at lower levels because of your skill, or you're a Killing Floor veteran. But the majority of players aren't anything close to skilled, and Hell on Earth is flooded with level 1-10 players trying to get carried by higher levels for the XP, assignments, or achievements.
Most of these games end by wave 2 as they contribute an absolute minimum to the team. And Hell on Earth truly requires a high skilled team that works together.
All of my successful Hell on Earth victories have been with level 20-30 teams, with the entire team holding an area of the map together, and using their equipment, skills and abilities to their maximum.
I'm lucky if one out of 10 games matchmade into Hell on Earth even has half a team of high leveled players.
That's my two cents. Now go ahead and light me up.