1. Erlang has a funky syntax; deal with it. If you can't or won't learn the language b/c of the syntax that is your loss. I'm sorry, but I can't really find this a valid argument as it basically sounds like "Erlang syntax scares me. Me no likey".
2. Documentation on Erlang libraries is a bit weak in some areas, but all the source is there and since it is functional, the ability to decipher the methods is really great. However, if you are looking for a 'mysql tutorial' with a 1000 hits on Google to show you the way, you won't find it. Frankly, you will have to exert some effort with Erlang.
3. This is wrong. I realize that this is 2008, but even in 2008 you had huge Erlang systems at Akamai, Mochi and many European telecoms. Since then (when I have picked it up) there is Basho, XMPP implementations, trading systems and, of course, Facebook chat.
4. Again, fear basically. The code base likely will never grow as big as a .NET or JEE code base simply b/c the code is functional.
5. The numbers are the numbers and they speak for themselves. You can't really understand the benefit you can get from Erlang until you try it for yourself on a multicore system and see it fly, watch it in a multi-noded system and watch it grow and see how it handles failures w/ ease. Traditional OO developers (.NET and Java) just won't "get it" until they try it.
6. Red herring. Erlang is NOT a web language. But, since this article was written many have emerged. Chicago Boss, Nitrogen, Erlang-web. I still think of Erlang has mostly an way to (coupled with Webmachine) expose some endpoints as services for me to talk to.
7. Yeah, this one is true. String manipulation sucks. Binary manipulation, however, is awesome. Tradeoffs. Remember what Erlang is good for and what it is not good for and you will be quite happy with it!
Erlang, in general, takes some time to learn. It is well worth the time if you need infrastructure that can scale massively.
Lastly, I would like to say this...functional programming in general is coming back in vogue at the moment and for good reason. Working on this system using Erlang has really reshaped my thoughts on programming in the past two years and I have to say that all my code is cleaner, my code base is smaller I have started to really take a critical look at my OO code as heavy weight and not worth the overhead in many cases. FP also seems to map better to my way of thinking....but that might just be me.
[EDIT] - Clarifying 6 a bit. I think that holding the web framework argument against Erlang is unjustified. Even so, web frameworks have emerged. I find they don't map very well and I feel there are better solutions than using Erlang web frameworks.