[bachmeier]

> You don't need to make your website fast, all you have to do is not make it slow in the first place.

This requires testing. Which is, apparently, something most companies don't know how to do correctly.

[NohatCoder]

Actually no, the point is if you don't put in anything that potentially makes the website slow you can be reasonably certain that it isn't. Obviously you still want to test the website, but it is not like this path is particularly test demanding.

[Spivak]

Automated performance regression testing in browsers isn't trivial. Hell automated correctness testing in browsers isn't trivial. It's just not a well-trodden path -- automating browsers to test anything at all is messy and brittle.