Considering that very few matters/game ideas/random thoughts need to be posted within an hour of each other, I disagree.
Now if that was restricted to certain boards (i.e., JFF, General,) then that would stop a large amount of spam thread incidents like this one (most spam threads are posted in General and JFF,) without hindering potentially important posts in Meme Research and Site-Related (I’m not sure how easily difference can be coded in.)
On the whole, anything that’s time intensive can be taken into the IRC, PM’d to various mods/admins, and/or communicated via email among mods/admins.
More simply, unless there’s a reason outside of “I would like to be able to post two JFF threads in an hour, because it would be annoying to wait,” I think preventing this sort of spam spree outweighs that by a lot.