There's many important points about the default browser:
- it needs to be stable and compatible with websites
- it needs to be fast
- it needs to be light on resources (ram) which is probably the biggest issue in all the browsers
- it needs to be compatible as much as possible (flash, java, youtube, Netflix, etc etc..)
- it needs to have all the features needed of a browser
Now, let's see that us we can have preference for a privacity browser like Tor, but that's probably not the case of the average users, I think an average user just wants to use a known (familiarized) browser and compatible with its gmail and other things like extensions bla bla, also, most of normal users really wants to be tracked by google and these things (its a user-experience improvement in fact), like showing the wanted results etc...
Also, the easiest way to know "which" is the browser that users REALLY prefer to use is by looking the website statistics, what is the most commonly used browser that enters to the elive website? (this concept includes "interest on elive" and "the browser that -them- want and uses in their daily life in their default os"), which is:
clearly chrome is the most used, so this one should be the default... for sure there can be alternative options to offer like how the installers asks which one to use but as a default seems like the chrome is the preferred by many reasons (and even more important are the first points listed, like the resources that consumes and the speed of it)
