Whaaa!
Stop pretending like the 3rd parties magically represent all the independents. The independents are largely indecisive, not looking for more options.
In most marketing scenarios the choices are between Coke & Pepsi, an incumbent or an alternative. Perot got into the debates in 1992, Anderson in 1980. There is no monopoly.
If Gary Johnson, or Rosanne Barr for that matter, had any traction with voters they could get on the stage as well.
The fact is these candidates don’t represent the independent voters either.
By that logic, 99 percent of the cars on the road should be either GM or Ford.