I can attest that this same feature exists in NBA 2K13 (hey, things get heated out there, what can I say?). Still, some gamers are taking exception to not being able to swear in their own living room without being penalized for it, so why does the feature exist?
Having been to a number of NBA games myself and sat up close, I've heard all kinds of profanity come from players on the court. Rarely are they T'd up for using foul language unless it's directed at the referee or if a player takes things too far, such as repeatedly complaining about a call well after the fact. At the same time, the NBA is ultra-sensitive about its image sometime, so there is a bit of realism there.
As for the feature being received so positively, well, that depends on who you talk to. The gamer in this YouTube video (NSFW - language) is hilariously caught off guard, especially after he just dropped a small fortune on the Xbox One.
In any event, you can get around the feature by disabling voice commands in the settings. It's kind of an all or nothing affair, but at least there's a way to avoid being penalized for your potty mouth. You're still on the honor system for tipping the swear jar, however.