What if Tank classes could only meatshield?

[Nektulos-Tuor]

What if in a world where upon entering a dungeon or raid, all of the Tank classes ability to do numerical Damage was completely removed and replaced with plain threat. The numbers you see when you activate a damaging weaponskill instead was aggro numbers generated.

What if STR meant nothing and VIT instead helped scaled your aggro generation much akin to how STR scales your damage.

Naturally skills and gear would be redesigned to this new idea but the question is; Would you play a tank design like this?

In a world where Tanks can only generate aggro and mitigate hits, healers can only heal and cast debuffs or whatever it is they do, and DPS were the focus of all damage on party to boss.

Would this be fine?

Question:
What if Tank classes could only meatshield?

DPS Classes/or Monk with Earth Stance (10% Damage Reduction) would be the new Tanks. People would also avoid dungeon and raid content then complain on the forums they have nothing to do. Developers would put more development time into Open World content instead because its fun and has no penalties and players seem to like it a lot more.

Experience=12 years of MMOing:
Every stupid developer or game who have tried to do this has been bent backwards and failed. It doesn't work.