The administrators claim its implementation was to prevent spammers like *****. This isn't really a good excuse as other networks don't have this rule and suffer the problem of spam more than Miiverse does.
After this update was revealed, Miiverse users began to rant about how it was an unnecessary rule. A lot of users started spamming with the hashtag #SaveMiiverse, hoping that whoever made the update would remove it. This was going on for about a week. The users Nahtasir and PSTP managed to spread the hashtag to the YouTube community. There was even a petition to remove the update. The petition against this rule can be found here: http://www.change.org/en-GB/petitions/nintendo-remove-the-3-minute-comment-restriction-on-miiverse.
"It is unknown if this horrible rule will ever be taken away to burn in depths of Hell..... Or the Blood Stained Sanctuary... LAWL Cave Story reference!! But seriously, this update sucks."
There was an update that lowered the time between comments from three minutes to two minutes. However, many users are still angered by this restriction. The Miiverse Redesign replaced this restriction with a limit of 30 posts and comments combined per day, but the restriction itself still exists as a 10-second-long delay between posts.