Earlier quoted context omitted.
Is a monoculture as bad as it might seem though? Front end web development is a clusterfuck. Webkit is open source, unlike the almost monoculture that ie6 represented. It can be forked and evolution can continue. Ditch -webkit -mos and -o. Like when the dinosaurs experienced a mass extinction event and mammals bloomed from a shrew into cats and humans.
The current monoculture is much worse. It's a monoculture where the developers are not supporting the popular thing because it's popular, but also because it's what they themselves prefer. This is much more dangerous and it spills over to other areas. If you walked into a coffee shop in San Francisco you'd be hard pressed to see anything other than macbooks, iphones, and chrome (maybe safari a little bit). So forget…
And you're right, there seems to be a strong tendency towards mutual masturbation over the web. "Make what I want" is leading to this tiny little house of mirrors.