Top 3 pitchers from each decade using fWAR:
1900: Cy Young, Christy Mathewson, Rube Waddell
1910: Walter Johnson, Grover Alexander, Eddie Cicotte*
1920: Dazzy Vance, Eppa Rixey, Grover Alexander
1930: Lefty Grove, Carl Hubbell, Paul Derringer*
1940: Hal Newhouser, Dutch Leonard*, Bob Feller
1950: Robin Roberts, Warren Spahn, Billy Pierce
1960: Bob Gibson, Jim Bunning, Juan Marichal
1970: Tom Seaver, Bert Blyleven, Gaylord Perry
(The top 9 from this decade are all inducted, including 4th place Ferguson Jenkins.
1980: Nolan Ryan, Bert Blyleven, Jack Morris (Stieb basically tied with Morris).
1990: Greg Maddux, Roger Clemens, Randy Johnson,
2000: Randy Johnson, Roy Halladay, Javier Vazquez*
2010: Clayton Kershaw, Max Scherzer, Justin Verlander
First, I just want to recognize that Grover Alexander and Randy Johnson were top 3 pitchers for 2 entire decades. There's some luck with the timing, but that's incredible achievement.
Anyways, it's clear that the author of the Stieb article used bWAR to illustrate his point and it's a good one. Even using fWAR, Stieb seems like a very obvious outlier. There are 4 other retired pitchers who didn't make the Hall of Fame and I'll address them below:
Eddie Cicotte was likely to make the Hall, but was banned from baseball. Not a great comp.
Paul Derringer and Dutch Leonard are good comps for Stieb in that they didn't do much outside of that decade. Unlike Stieb though, they played on bad teams and both ended up with a .513 win percentage, which certainly hurt both players. Derringer once went 7-27 with an ERA+ of 103, which is insane. If we're being honest though, both pitchers probably have a better Hall of Fame case than Stieb, even with the bias in the awards voting considered.
Vazquez' only real similarity with Steib is that he pitched in Canada and was ignored by voters in truly stunning fashion. The argument is that he was never truly dominant and just pitched a lot of innings, which is somewhat true, but we can't ignore the fact that he was right there with guys like the Big Unit and Doc for the span of a decade.
Does Stieb deserve to be in? I enjoy reading the arguments, but he didn't pitch enough in my opinion.