I hate /blog/ prefix in my multisite installations
As far as I can see this was an arbitrary addition to the 3.1 version.
I couldn't find a single ticket (Trac) or suggestion (Ideas) about this.
Fact is I use WP for several companies as a CMS solution.
Unfortunately some of the companies use proxy blockers to filter employees access to the web. Now guess on of the most popular words they commonly block... BLOG !!
So the employees can't access blogspot and so, but they can't also access their own company's posts becouse of the infamous mandatory /blog/ prefix
My idea for a solution is to set this "compatibility mode" to avoid conflicts as optional in the main settings page. In addition the word 'blog' should be optional too, if I like 'news' instead, there would be no problem with proxies, blockers, etc.?
As a conclusion, each scenario is different, we cannot impose a (commonly blocked) word as a mandatory prefix if we want to keep growing in the professional market.