"Babel" set a dangerous precedent for the budding series. It was the first time you didn't need to particular care for the premise to watch. Basically, if the premise of a series like Deep Space Nine, particularly in the first handful of episodes, doesn't matter in a story, then that story doesn't really matter. Yet it probably seemed like a good way to soften the moody impact early episodes had already had on fans.
"Babel" is a fairly typical franchise entry, something the creators probably thought was a good thing, but it ends up being so nonspecific that it feels like maybe the series wasn't as cutting edge as it thought it was. A malady spreads across the station, leaving everyone to speak in gibberish. That's about it. It's a little fun to watch actually develop, especially the moment Sisko realizes his son has been affected (probably the first time since the pilot that either of them have really been relevant, especially in relation to each other), but otherwise...mostly forgettable.
franchise * series * essential * character
Memory Alpha summary.