I'm not sure if that does show politics is messed up. Looking at it the other way, being Prime Minister is a job that requires many different skills, including managerial skills, understanding-policy skills, having some kind of vision, and being able to inspire people (very important because, amongst other things, being PM means holding a diverse group of people together and persuading a lot of people in your party to go along with things they possibly don't like). If you don't have the ability to inspire people with some kind of vision, then arguably you're lacking one of the skills to do the job.
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Look at the 'boring' PMs we've had in recent history: John Major, Gordon Brown, Theresa May. John Major and Theresa May both lead Governments that ultimately spectacularly failed in part because they weren't able to inspire/rally their own MPs to support what they were trying to do. Gordon Brown's Government failed for other reasons but reasons that weren't entirely unrelated to his lack of charisma.