Chuck Knox took over a 3 - 11 team in 1978 and had the Bills in the playoffs by 1980. Marv Levy took over a 2 - 14 team in 1985 and made the playoffs by 1980; both efforts had great drafts and the Levy team stayed in the hunt for 12 years - to include Wade Phillips time. This team made horrible coaching, scouting, and drafting decisions throughout a 17 year period creating a culture of mediocrity - I remember posters on TBD thinking we were only a player away when in truth we were not even close. You don't fix 17 years of dysfunction in a "short amount of time" when you have to construct a new organization and culture. McBeane is in year three and has one playoff game under his belt and 2019 is shaping up pretty well, building an organization based on long term culture and character not fly by night divas!
And yes, the young fan base has earned their stripes as you say, but so have those of us that lived through 1968, 1976, 1977, 1984, and 1985 - you can't even imagine the pain!