I'm sure the F-15 had its detractors while it was still in development like most weapons systems. Designed to be an air superiority fighter and fifty years later, still undefeated.
I'd say it delivered as promised.
The F-15 (and F-14) were contenders until as late as 1979 -- but once Trudeau's Liberal Party won in 1980 the choice was immediately narrowed to the F-16 and F-18.