To me this is the classic game night overreaction. Who do you plan to replace Miles with? What is Miles' record in 9+ seasons? How many coaches have won more games? Be careful what you wish for...
I have a feeling it would take more than just a QB change to avoid three more losses. Neither QB is a game changer, the offensive line isn't as good as it was projected in preseason, and Bugga Fournette isn't the Michael Jordan of college football or Adrian Peterson. Further, this isn't a defense that will carry the tigers through the season.
And it may be, your opinion matters most to you. For me, I find it impossible to believe that LEM is the only dude that can accomplish this at a place like LSU. I know he isn't. He is outcoached all the damn time but often wins because of the talent that is on the field. I'm tired of his act, was a long time ago. I know he isn't going anywhere, not until he is ready to but I certainly cannot wait for that day to come.
I'm as unhappy with losses to teams we should beat and with Miles shortcomings as much as anyone. That being said be careful what you ask for. Miles does many more things right than he does wrong. The overall product while underachieving still beats a large majority of what you see out there. Texas, Florida, Michigan, Ohio State, USC, Miami, Notre Dame, Penn state. Those are just a handful of once great programs that were dream jobs at one time. Places where things were so good any old coach would have success. Miles isn't great at the x's and o's but he's about as good as it gets at just about everything else it takes to be a great HC. That's why it's really important for him to surround himself with great assistants that he trusts enough to give them complete control. Giving up the control is what appears to be the problem to me. Ask yourself how many programs you would trade places with? As frustrated as we get with Miles I bet it's still a very short list.