There's a flaw in your logic which makes it seem like blasphemy. It's not enough to say that there aren't many .NET examples; you have to show that the proportion of .NET people who do good .NET work is lower than the proportion of PHP/etc. people who do good PHP/etc. work. With PHP in particular, I would guess that it's easily true that a higher proportion in .NET would be better equipped.
Not good work. We're not talking about good work. We're talking about fast work that runs on the web, works at scale, and allows the organization to pivot easily. You certainly won't catch me suggesting PHP is some sort of awesome language.. it's not. But it's language that lives on the web, and if I was building something on the web and had my pick of a random .NET developer and a random PHP one, I'd take the PHP one... because chances are the .NET developer has never deployed something on the internet, and chances are the PHP dev has.