I loved the most second sentence, where I read hidden message "serve user-space well or the user-space will come haunt to kernel-space, then anyone will not have fun".
My add: In the end one better to make it clear, on top of user-space and everything sits (or shits) the user. Crap have to flow both ways, if it is plays between.
My addition has a reference to quote of Andrew Morton above Torvald's.