True, but then there are situations like Rails, where 37 Signals could have built their apps using existing tech, but said 'there should be a better way'. I mean, if you told someone "I'm building this project management app, and I'm going to take an esoteric language no one knows, and write an app framework from scratch" they'd rightly tell you you're crazy.

Most endeavours that start like that end up as failures, however without these attempts tech would stagnate.