I often see Emacs newbies stealing hundreds of LOCs from different sites, only to end up with a lot of added complexity that is hard to understand let alone maintain. I imagine it's the same for Vim.
Emacs defaults are quite usable. I've been using Emacs for 15 years and I'm only altering a dozen variables. The rest of my .emacs is simply use-package directives. As I become more proficient, I trim down my dotfiles, not the other way round.
Some defaults seem to be there for historical reasons. When I see such a thing, I wait a few months. If I'm still convinced the default is legacy code, I try to lobby for a change. I've found that developers tend to be very receptive if changes can be well justified. E.g. there's a long discussion now in emacs-devel on how to modernize many defaults and make the editor more friendly.
My goal is to push all my dotfiles upstream, and end up with almost empty configurations. And I'm getting there.
Every few months, if I'm not 100% on the utility of a customization/package, I'll remove it and see if I survive without it.
This beats having to declare config bankruptcy.
Anyway, this stance seems to be what separates conservative from a liberal. Conservative want to protect something that exists but he has no knowledge of reason - such as people protecting slavery, racism, etc. Putting up barriers against people trying to change world for the better.
2. It's not hard to come up with reasons for slavery and racism to exist; that's all you need to do to satisfy Chesterton. I'll even go a step further and say that for societal issues if you don't have at least a basic understanding of the forces that caused them to exist (and cause them to continue to exist), then you will probably fail to change them anyways.
3. Fences take time to build. It's very rare that you get eccentric people putting fences up randomly (rare enough that discovering that to be the cause of a fence should be pretty easy because it would be so notable!)
4. Because of all of the above, I'm going to say that it's not really the difference between a conservative and a liberal, but it is part of the reason why younger people tend to be more liberal and older people tend to be more conservative. Understanding the lesson of unintended consequences puts pressure on the "conservative" side of the scale, and it can be an excuse for conservatism. However, Chesterton's fence is an important engineering principle that should be taken into account when making policy regardless of your political leanings.