One problem is that the `/r/:subreddit` url creates name-squatting and the illusion of canonical forums.

/r/canada is like <company>.com: anything else looks second-rate. /r/canada2? /r/bettercanada? /r/altcanada? /r/the_canada? /r/mapleleaf?

I think reddit should've gone with `/r/:username/:subreddit` to remind everyone that every subreddit is just some random person's forum, not some canonical message board on that topic. It also makes it much easier to migrate to another subreddit because you aren't stuck picking some second-rate subreddit name like /r/bitcoin -> /r/btc.

/r/spez/politics, for example, reminds you that it's the politics of whoever spez is (reddit co-founder) and his mod team.