As someone who resolved economic issues that even Zhuge Liang found intractable, his abilities were indeed exceptional. However, this guy was a die-hard fan of Cao Cao, a staunch anti-Liu Bei supporter. Even when Zhuge Liang cornered him and forced him to resolve Liu Bei's financial issues, he was always ready to follow Cao Cao while he was alive.
It is worth mentioning that even after being captured by Liu Bei, who treated him quite well, he still thought about escaping Shu Region to follow Cao Cao, until Cao Cao passed away.
In sum, Liu Ba was a strange supporter of Cao Cao against Liu Bei, yet still a high-ranking official under Liu Bei. More importantly, he made no effort to hide his desire to join Cao Cao. It's assumed everyone under Liu Bei knew that this person didn't want to serve Liu Bei and wanted to go to Cao Cao instead.
