Why would you make it require Yosemite 10.10? This is absurd developer laziness. Spend an hour making it compatible with OS versions from the last couple of years.
The forum software "Discourse" is a good example of hugely over-engineered bloat and Javascript being required to display some text.
They even require that you have the latest smartphone hardware! To display a forum post!
As with the examples of Facebook and Google, these are intelligent people working at these companies. Yet they get it completely and catastrophically wrong...
Indeed, it seems like wishful thinking that Atom will magically become quicker. One presumes that the easy optimisations have already been made. What else can be done, other than a complete rewrite using a different technology stack?