What are you trying to say? The number of guys who rarely pitched 7+ innings in their first 25 starts and didn't turn into Cy Young contenders is probably a lot longer than this list...
Plus, like May, most of those guys either spent time in the bullpen or being demoted to the minors after their debuts. And I think a lot of Lester's starts were innings-limited because he was recovering from cancer treatment.
That said, I'm not rooting for May to fail by any means. But he's certainly got some things to work out, and I'm looking forward to seeing if he's been able to address them from his time in the bullpen.
My point is that an inability to go 7 innings is no reason to send a guy back to the minors. Some players just have to work through that. They don't know how to get major leaguers out efficiently to start and having them pitch in AAA doesn't help that. Some guys have it right away and can be efficent with their pitches and get guys out from the get go. Other guys aren't efficient right away but improve with major league experience. At this point, May should be pitching in a Major League rotation to help his improvement. He has shown enough improvement to keep going.
I think the fact that the Twins are contending this year was a big surprise and because of that, May got bumped to the bullpen to help the team out. If they were out of teh playoff picture, I think he'd have a rotation spot.
Actually, only one of those guys were demoted to the bullpen or the minors after their debut. Jon Lester threw at least 90 pitches in every start his rookie year, but only went 7 innings once. This was pre-cancer. Post-cancer he never thew less than 90 pitches every game as well.
David Price started in the bullpen for a playoff team, but once he joined the rotation the next year, he was never sent back to the minors or to the bullpen. That "rookie" starting season, he averaged 5.6 innings per start, had a 4.42 ERA and walked 3.8 per 9 innings.
Sabathia never was sent back to the minors even though he averaged less than 5.5 innings per start, had a 4.4 ERA and walked nearly 5 per 9 innings.
Kerhsaw never was sent back to the minors even though he averaged only 5 innings per start, had a 4.26 ERA and walked 4.3 per 9 innings.
Max Scherzer did get sent to the bullpen in his rookie year and got sent to the minors then back to the rotation in September. Only had 7 starts that year. In his second year, he started 30 games, only went 7 innings 6 times, had a 4.12 ERA and
Cueto was never sent back to the minors or the bullpen. He had a 4.81 ERA his rookie year, averaging 5.6 innings per game and walking 3.5 per game.
In May's career, he's averaging 5 innings per start, has a 5.32 ERA, has a walk rate better than Price, Sabathia, Kershaw and Cueto did and has a strikeout rate on par with any of them that early in their career.