Stop making so much sense, straw man!

I've been on Twitter for a good year or so now, and there's one thing I don't really understand. I follow several actors on there, which is one of the main draws for Twitter. And many of these actors, being human beings, have political views. Sometimes strong political views, which they like to express on social media like Twitter. All of this is perfectly normal. What I don't get is when people who disagree with some actor's political views level ad hominem attacks against the actor, rather than address the actual issue.

Of course, ad hominem attacks are nothing unusual in and of themselves. There wouldn't be a word for it otherwise. And it's Latin, so there's nothing new in this idea.The thing about it is that the attacks are usually along the lines of "Don't you hate it when washed-up has-beens try to get involved in politics?" What does one's fame (or current lack thereof) have to do with anything? How does being on a television show disqualify you from having an opinion?

I've been trying to determine the line of thinking that leads to this kind of comment, and while I'm sure it's not a conscious process, I imagine it goes something like this.

1) The person making this comment has an opinion that differs from mine.
2) My opinion is the (only) correct one.
3) I don't have enough information to defend my position in any meaningful manner.
4) Childish insults are my only recourse.
5) When I think of this person who disagrees with me, all I can think of is something s/he did in the past which gave them a measure of celebrity.
6) Therefore, that must be the only thing the celebrity can think of him/herself.
7) I am jealous of that celebrity.
8) I will attack the person from that angle.
9) The celebrity will either see the error of his/her ways, and/or retreat into a dark corner and weep uncontrollably.
10) The world shall crown me Grand High Victor of the Universe.

Ok, I went a little overboard at the end there.

-Long Days and Pleasant Nights