You're right, .NET (even though I despise it) scales as well as anything else. Scalability is much more about design decisions than language/platform choice.
However, Joel Spolsky is a tool. Everyone I know and respect thinks he's a tool. He is a prime example of being successful because of being lucky, rather than being good. Do not quote Joel, he can't form a valid argument for a topic without circling back on himself to save his life.
Actually, that article is one of the most interesting and useful examples to point to when discussing the insanity that is Joel. That solution is just so ridiculous.
His software runs on a compiler that has had 2 months work put into it and worse, it compiles to either VBScript or PHP.
It's probably the most counter-intuitive solution ever implemented to solve the problem of needing a web-based application to run on both Windows and Linux.
Except when it came time to move to .NET/Mono, they only had to update their compiler to generate IL instead of rewriting the whole app from scratch. Sounds smart to me.
Except they are still stuck with any badly implemented language "features" in their own language that they only spent 2 months on. Language design and implementation is hard, just ask the dozens/hundreds of full time developers that work on ruby, java, php or .net itself.
Do you have inside knowledge of their framework? Did you know wasabi has memoization and heap of other things frameworks like .NET don't even have? They spent a lot more than 2 months on Wasabi. I think your information is outdated.
Whether Joel Spolsky is or is not a tool, lucky, good etc is completely irrelevant. He and the rest of the SE/SO team has built a highly scalable solution based on .NET. So in a discussion about scaling on .NET, it absolutely makes sense to listen to his experiences.
Actually, FogBugz is trivial to scale - there is never any more than a few dozen, to hundreds of users for any one project.
And Copilot wasn't even envisaged or created by Joel, but was rather a project created by some interns.
FogCreek doesn't innovate (they have a bug tracker and a remote support application based on VNC). Joel just happened to be one of the first to blog constantly about technology. He doesn't even allow comments on his posts because he doesn't want to have to deal with people contradicting him (not that he doesn't do an excellent job at this himself).
There are so many great developers and businesses out there that you could use as an example to model your business and software on. Use them, not Joel. Let Joel's business and opinions fade away as other smart, innovative companies run rings around his ageing product suite.
Someone approached hiwith the idea for that product, it wasn't his.
Besides, this is a perfect example of him contradicting himself about how taking VC is a bad idea.
Besides, do you think they are profitable yet? How do you think they will get there without heading down the Expert's Exchange track? And let's not forget how much chaff is now being added every day to these sites, it now seems to be impossible to ask a difficult question because only relative newbies seem to be the only ones answering questions.
However, Joel Spolsky is a tool. Everyone I know and respect thinks he's a tool. He is a prime example of being successful because of being lucky, rather than being good. Do not quote Joel, he can't form a valid argument for a topic without circling back on himself to save his life.