It was exactly this attitude in Firefox's early days that put off a lot of non technical (or "non enlightened", to use the phrase that was popular at the time) users.

I'd like to know what measure you are comparing FF with other browsers?

The fact that it's OSS, addons, customization capability, JS engine, and mostly, privacy/security.

Also I dislike most of direction Chrome is trying to lead Internet - namely NaCl, Dart (I'd prefer a proper), etc. FF on the other hand made pdf.js which made PDFs viewable in any browser that suppots modern JavaScript.

Chrome never made a project to parse and present all pdf, just internalized PDF reader (truth be told, Mozilla nabbed the man that built pdf.js).

I think you meant to say Chromium.

Depends on the trust you place on Google, as opposed to the whole web. Hence, "mostly".