Personal taste = Fair enough.
Trying to make a point saying a man that's only really done two things since 2005 (one an award winning web-series) is dated and only Internet geeks like him. = 
Of course shows that are six years and older will be dated today.
Dollhouse was terrible.
Firefly didn't feel fresh at all. Can't understand people's love for it. A Western in Space, I get it, but the characters and the plot were just.. average (at best). As for the 'he was around before the internet was big' comment. He was around for the vocal internet's youth, they grow up on Buffy, and now champion him on the internet 10 years on.
Its not so much the content of the pop culture reference he used that dates the show, its the fact that he always goes for it. I associate it with the MTV 90s cheap TV. I need a joke, OK, I know, random pop culture quip, everyone loves them and they're easy to write!
Dr. Horrible is the web series, not Dollhouse.
Now to translate the opening bit of your post:
Firefly didn't feel fresh at all to me. I can't understand why people like other things than me.
Your comment about the Internet geekdom is still just silly. What about LOST, if any recent show has had an online geekdom it's that show. Or Smallville. Or Supernatural. Or The OC. Or One Tree Hill. Can you see the pattern? It's shows aimed at tweenies. (With the exception of LOST), with the way Internet is being used today these shows tend to be discussed a lot online, as other things that people enjoy (such as NUFC and football in general for one). There's actually very few people left that are hardcore Whedon lovers online these days as they've moved on. Sure, there are Buffy/Angel lovers, but these as well did not enjoy Dollhouse. It's really quite simple, you don't like Whedon and don't rate his shows as "good". Why try to label it as something else? There's loads of people I don't enjoy the work of, I don't try to make up s*** about their fans only being Internet geeks. I just say I'm not too fond of that particular person and/or film/show.
There's fans of everything online, to single out one of the smaller groups (at the moment) and try to use them as an argument as to why you're not a fan of someone is downright silly. The issue is clear, as said before, you're just not a fan of Whedon and thus you don't enjoy discussing Whedon. Hence everyone that does enjoy Whedon is an "Internet geek", just as every person supporting, say, Chelsea, is a mindless fuckwit. (just an example, you've not said that.)
How do I fall into the group of a Whedon Internet Geek by the way? I mention on here why I am a fan of his and why I enjoy his work. I don't go around all over the net proclaiming my love for him, I don't throw his name into every other sentence unless it's the subject of conversation. I enjoyed LOST, and when that's the subject of conversation I talk about why I like LOST. I enjoy The Sopranos, and when that is the subject of conversation I enjoy talking about just why I love that show. These are all shows that are created by people I like, and that I one day hope to be at least 1% as good as when it comes to what I do. If it's the subject of conversation in everyday life as well, or during work, I also enjoy talking about it, because it's something that interests me and I enjoy. To try to use an argument that because I like Whedon I'm an "Internet geek" is insulting, and quite frankly based on nothing else than your own particular like/dislike of said person. You don't enjoy his style, hence everybody else that does is wrong. Don't you see how that's an incorrect way to go about things?
I could go on and use other examples as well, but then again, if I did anyone who enjoyed these examples would probably be an Internet geek as well. It's YEARS since Whedon was the king of the Internet, man. It was back when his good shows were still on air. If you want to start saying someone is the "champion of the Internets" you'd be better off saying it's J.J. Abrams, because at least he's still a hot topic when television or movies are being discussed.
And if you knew anything about writing, you'd know that to get in a pop culture reference that
work is f***ing hard, not easy.
