When I read the article on 37 Signals in Wired, I admit I alternated between shaking my head, laughing, and sighing.
When Hanson commented upon the term arrogance, I laughed:
"Arrogant is usually something you hurl at somebody as an insult," Hansson said. "But when I actually looked it up — having an aggravated sense of one's own importance or abilities' — I thought, sure."
When the article describes him as a "philosopher king" I shook my head. And his response to naysayers, "F--- you" made me sigh; not a convincing piece of rhetoric at all.
It's not that I'm one of the fanboys of the Ruby or Apple world, or that I agree with Hansson's attitude towards windows developers - it's that I think it's a trait of people I call successful to be able to concentrate and get things done without regard for outside opinions. It's less of a "stay the course" mentality than an understanding of self and drawing clear lines with work rather than spending a lot of time second guessing and self doubting.
One area in which I can look at hard data and side with 37signals is in the realm of additional or complex features; I really do question whether they are worth it. I just recently quantified this with an application we wrote for a customer that they are using successfully. I compared the baseline functionality of a particular feature to some exceptional scenarios I had to write code for - it was easy because one can tell the usage by counting records in the database. Anyhow, for the baseline functionality I counted some 6,100 instances of its use. For the exceptional scenarios, I counted 9 entries. Here's the clincher: it took about 3 or 4 times as long to implement support for the exceptional scenarios (and it added a lot of complexity to the code for the baseline feature). So the ability to handle about one tenth of a percent of scenarios, cost and complexity was inflated significantly.
Here's where I disagree with them: it's not my decision, it's the customer's. My goal should be to communicate that trade off as well as I can.