What's the reason for a 7* Champ requirement gate in WOW Gauntlet?

The individual fights that panned throughout the weeks had certain champ requirements but were not gated to rarity. With the gauntlet dropped, why limit champ based on rarity to complete/ explore the quest?
Thoughts?
Thoughts?
4
Comments
Rather than certain tags, they just made it so that you had to bring a couple 7* on one path, 1 7* on the other.
Kabam don't want to make exclusive content for 7*, yet.
And there already make a permanent shoting star
If you could have either:
1. Class based objectives with some 7-star restrictions
2. Tagged based objectives and no 7-star restrictions
I know I would prefer #1. I would much rather be able to complete as many objectives in one run than have to rerun annoying fights multiple times. Spiderham's evade annoys me to no end everytime I have to face him in difficult content.
The side benefit is that it forces players to use 7-star champions that might not normally use, and make players appreciate non-Herc type champions. I know that my appreciation of Gamora has risen dramatically after doing a Cosmic only run.