Informed Wrongness: As the commentary notes, Homer is vilified for destroying Herb's company, when Herb himself actually shares a good deal of the blame for letting someone with no experience take over his new car's design, giving him no supervision, and even ignoring his board's attempts to tell him what a disaster Homer is making. Homer was in fact cooperative (and borderline subordinated) to the team's more conventional plans until Herb convinced him to take a stand.
The pompousness of the board themselves only exacerbated the matter. They quickly lost patience with Homer's ineptness with the process (which, despite being interpreted to make him an unbearable idiot, seems pretty expectant from someone with no experience of the industry) and shooed him away, leading Herb to stand up for him and make them do the job they were told. Even before the project goes completely haywire, the leader is quick to make a complaint, heavily implied to be loaded with gratuitous personal insults that likely only further led to Herb not taking them seriously. Even worse, before Homer arrived, the board was manufacturing cars that didn't cover the entirety of the market; the plot started because Herb was offering Homer a free car, only for Homer to be told "Americans don't want X" every time he requested something. Homer screwed up, but only after being corrupted by the unprofessional conflict between the company and their boss.
Jerkass Woobie: In contrast to Mean Boss on the main page. Much of the reason Herb is such, is because by his own admission he's a very lonely man. This turned out to be the case when he found out about his brother Homer. He was overjoyed at knowing he had a long lost sibling. However that joy wouldn't last.
The Scrappy: Herb for blaming homer for bankrupting him and his company, even though it was his own fault.
Unintentionally Unsympathetic: Herb. The episode tries to paint Homer as the one responsible for destroying his company, but as described above, Herb himself was the one who came up with the idea and exacerbated the problem by refusing to listen to any of his employee's warnings.
What an Idiot: You're Herb Powell, auto tycoon, and your company is on thin ice. What do you do to turn things around? Update your market research on what consumers want? Shut down money-losing product lines and focus on profitable winners? Replace underperforming board members with fresh talent? Or do you turn to your brother, an unassuming guy with zero knowledge of the auto industry, expect him to design a car that will magically fix all your company's problems, put all your company's eggs in this one basket, hang out with your brother's family instead of actually doing your job as CEO and supervise your brother's project, blow off your staff's warnings about your brother's absurd designs, approve his designs sight unseen, all while hyping the project as the auto industry's second coming of Christ? And then, when your brother's project destroys your reputation and reduces you to a laughingstock (and rightfully so), and your company is bought up by the Japanese, do you actually accept some kind of responsibility for your gong show, or do you just make your brother a convenient scapegoat?