[cnp]

Code normalization: that's the key. Once you've got everything working everywhere via a base scaffold -- the hard part -- then you can very quickly iterate on design changes, or design in general. Bootstrap et al are generally quite easy to tweak once you understand how all of the components fit, and i'm sorry but CSS just isn't fun to have to write from scratch, especially on bigger projects.

IMO, if I were to arrive on a new project and saw the front-end devs reinventing the wheel, it would immediately set off a red flag.

[egoodberry]

"i'm sorry but CSS just isn't fun to have to write from scratch"

That may be your problem. Maybe I'm a glutton for punishment, but I especially enjoy this type of work.