Oh wow, better stand back! The flack is going to fly! That question will get a lot of responses from dedicated users.
Ok, I will start off. I have been using FireFox for years, so to be honest I am not that well acquainted with Chrome. I used it for a while but was not impressed and could not customize it as I wanted so I switched to FF and never looked back.
Firefox big attraction is its use of Add-ons. There are literally dozens to choose from, are free, and you can customize FF depending on what you want. So it can be locked down quite well for privacy and security. I won't go into all the different security features that it has, but in general add-ons can prevent virus infections through Java and Active X (which is a major source of infected websites and "drive-by" virus intrusions), tracking cookies that track you wherever you go and can be traced by businesses for marketing purposes, the infamous NID and PREF cookies that are on most computers (without the user's knowledge) that Google uses to track you individually and that the NSA uses for the same purpose including hacking in to a computer that has them, as well as useful tools.
It is easy to learn, takes minimal resources, and is supported by Mozilla organization which is not a big business that wants to throw ads at you but a dedicated organization of geeks.
I have put FF on dozens of client's computers, installed security add-ons and they love it. In a nutshell those are my reasons, and in 15 years of using FF and no virus infections I still have the same opinion.
Edited by ranchhand_, 29 September 2016 - 12:01 PM.