That wouldn't make people shut up about Morrigan, though.
What would be particularly delicious about Zero is that while everyone has been saying Zero is the best character in the game since Ultimate came out, no one has really proven it. Zero players are bitter and angsty because they can't fulfill the potential of their character. If ChrisG did it, it would be a big smack in the face.
So, in that spirit, ChrisG would have to not use Morrigan or Doom, since then people would attribute his wins to those characters. Unless it were Plasma Beam.
And the pattern will never end, because the average player just doesn't understand assist utility. I still remember how all of Vanilla was plagued by people saying Haggar is "low tier", and when Viscant won Evo everyone said "nerf Dark Phoenix!", even though Wesker + Double Lariat won him a huge number of his matches.
Wesker/Haggar wasn't more effective in spite of Dark Phoenix it WAS more effective BECAUSE of Dark Phoenix. Viscant could afford to dictate the pace of the match as he pleased simply because everyone was so desperate to get rid of phoenix.
Half the game is already decided at the start screen. Then another one 1/4 is simply waiting to see who gets the first hit and converts best. Then it's pretty much a wrap.
Another thing is the meter system. The fact that you get 1 meter at the start has always been a problem simply because the potential abuse is so great. It's what made Phoenix go from a 5 bar character to a 4 bar character.
With that 1st bar morrigan already has what she needs to do her work effectively. With other characters you need 2. And unless you have another meter building assist on your team the best way you get that extra meter is to hit your opponent. And that's why Morrigan is so powerful: She doesn't have to rush you down to build meter in a game where in order to beat her you need to rush her down to build meter. And in a game where meter building is already nerfed to begin with, this is critical.
The best way to beat morrigan is to kill her at the start of the game. Of course that's as easy as saying "kill Wesker and Haggar before Phoenix gets 5 bars." But it is where she is indisputably the weakest.
The next best way is to stall out AV while preventing her from gaining meter. RR and Flight characters are pretty good at this. Thor gets special attention because Mighty Strike can nullify projectiles, can be done in the air, AND has super armor. He can also afford to take doom missiles better than most characters due to his health, and taking the missiles resets air actions as well. After AV is over go in.
Killing Doom is obvious but also the most impractical. You need 2 meters and xfactor, which is practically impossible to build. Not to mention that IF you are building meter while hitting morrigan then you should just spend the meter to kill her. If you are building meter while getting hit... you probably won't be in any position to THC. Not to mention she can steal your meter as well.
Basically like phoenix you aren't also fighting the character, you're fighting the meter system.