microsoft has a bad history of misjudging the quality of games, and that goes both ways
Examples, please. Specifically games that they said were awful that turned out to be good. If it's a frequent thing, sure, but I can't even name any isolated incidents.
either way games like halo wars 2 and crackdown series aren't huge titles


Halo Wars 2 is in the top 100 and is the best selling console RTS of all time (and will still be on Xbox One, as well as Windows 10), while Crackdown is in the top 130 and flattened games like Black Ops 3, FIFA16, Dishonored, RAGE and many other games on the Xbox 360.
Both games are financially successful franchises for Microsoft's platform with a history and reputation. Scalebound might have a developer with history, but it's a brand new IP, and clearly the gameplay didn't stack up.
just serve as low quality money grabbers. if they did scalebound right it would pull in a huge amount of money
Subjective statements, given the only way to known that information would be to see the playtest data (or have a magic crystal ball), which Microsoft holds. Microsoft put a
lot of money into first/second party developers when publishing; if they can't make a profit, that's the end of the road.
but couldnt they just have redone scalebound instead of just trashing it all?
Microsoft has presumably already spent a
large sum of money to fund development for the title (as-is their role of the publisher). Restarting the project would mean essentially writing off all that cash as a loss AND THEN refunding the entire damn project to the same or higher amount. And, what guarentee would Microsoft have that they'd do better this time around? If it's the same people...