Satch vs. Mustaine

On YouTube, I subscribe to some Guitar Center channel and on it there are some pretty sweet videos. They have this series called In Session or something of that nature. The short and skinny of them is this: get a famous guitar player and have them tell some stories about their tunes, play their tunes, and interact with the audience. Sounds simple right? Well what I am going to do here is compare and contrast two guitarists they had on there; one is Joe Satriani and the other is Dave Mustaine.
So on one hand, we have Satch. Super smart, creative, and a virtuosic player. He also happens to be a nice, funny, and engaging person. He talks about his songs in a technical but very accessible way and also is self effacing about  the whole thing. He also cracks jokes, talks to the fans, describes things relating to gear, music, and inspiration. How cool is that?
On the other hand, we have Dave Mustaine. Again, he is creative and smart; no where near the level of Satch (this is not an opinion, it's a simple truth). Yet during his In Session, he couldn't look more annoyed or bothered to be there. It looked like it was such a chore for him to play his songs, talk about them, and talk about them. Also he is not engaging, not even a little bit. That leads me to ask why? Seriously how bad is his life here? All he is doing is answering questions and telling some stories about his songs. He also can't help but bad mouth ex band mates  (surprise, surprise huh?). I mean the whole point of this is that you are celebrated for your playing by Guitar Center and the fans, and also have a good time. But he can't just have a good god damn time.
I mean I like them both for different reasons, but these things also showcase what type of person/personality they have. One guy can't be having a better time, while another guy just seems to be dragging a dark cloud with him because it is impossible to find joy in something (when he does,  it seems SUPER awkward). I guess if I were able to hang out with one guy, it would be Satch. I've met him and these videos also give an insight into how much a nice guy he is...and what a turd Mustaine is 96% of his day/life.