well it is quite a shallow opinion really, whether it's a harsh fact or purely fiction. however, you pointed out two wider issues with his leadership yourself and at that time thatcher won her elections based on her policies over her image in my personal opinion.
But the point is that it's not "MY" shallow opinion. I'm not judging anyone's abilities based on how they look, I'm looking at the evidence and the evidence is suggesting now that you won't become PM of this country unless you look a certain way and perform well on TV. I think it's sad that a bald man would probably never win an election today, but the fact we haven't had a bald PM for many decades (and the party leaders are getting younger) tells its own story.
Similarly, if Jenkins was ugly (or even plain), would she be famous? Seriously?