Developer of Solarized here. Glad that it continues to be a popular design. I've let the github languish and regret that. Luckily since it's just a color scheme the website and info on github has been enough for it to continue to propagate. There have been plenty of other color schemes that I think it's safe to say have been inspired by Solarized and this is very satisfying to see. Many of them have done a better job…
1) I don't use Solarized everywhere religiously. I use it a LOT, no surprise. Still my preferred color scheme in most editing, terminal, code situations. But I am happy to use other well designed colorschemes in various contexts (writing, task management apps, etc.). Even when Solarized is available, sometimes variety is what's called for.
2) Solarized was designed to enable the colors to be used in high contrast modes as well. As my eyes age I sometimes will apply the colorscheme in a higher contrast mode. This adaptability is sometimes overlooked but it is inherent and intentional to the design.