I follow Blow's work and opinions quite closely. I am quite confident he was NOT criticizing Mighty specifically. Instead he was deploring the state of software engineering in general and web programming in particular. He is saying something like "I can't believe web engineering sucks so bad that a tool like Mighty actually makes sense". See his talk about preventing the end of civilization (!!):
Definitely highlights something I've always felt, which is that we're really making life complicated with all those tools and processes that are less than ideal.
I get the feeling business and the need to "ship" stuff is the thing really bringing technology down, even though it looks like it's moving it forward.
https://www.youtube.com/watch?v=pW-SOdj4Kkk