I think it's because SPA web development is like using a hammer made of chewing gum to build a house, and the ridiculous toolchains necessary to build a solid hammer always look complicated and unnecessary.
EDIT: What I mean here is that the foundations of the web weren't designed for application development and are missing some crucial bits and pieces like encapsulation. The tooling necessary to encapsulate CSS in a way that works with every browser is complicated, and if you've only worked on small to medium projects it can be hard to see the need for such complication.
EDIT: What I mean here is that the foundations of the web weren't designed for application development and are missing some crucial bits and pieces like encapsulation. The tooling necessary to encapsulate CSS in a way that works with every browser is complicated, and if you've only worked on small to medium projects it can be hard to see the need for such complication.