Fighting after a cheap-shot has exactly one purpose: to fulfill a primal sense of revenge for one's team. It doesn't cure the injured player. It doesn't prevent a cheap shot from happening. It doesn't discourage players from doing it again after they've already committed the cheap-shot. In fact, it has been demonstrated repeatedly that teams with more fighting majors actually tend to have more injuries and stick infarction penalties against, which would suggest that fights actually increase the amount of cheap shots you receive, which is the complete opposite of "keeping the opposition honest". This has been repeatedly demonstrated on separate occasions by separate people (a few sources for the curious: http://regressing.de...-don-1442618145, http://www.pensionpl...ness-in-hockey, http://blogs.edmontonjournal.com/2013/09/30/the-edmonton-oilers-and-the-new-era-of-the-one-dimensional-fighter/). Its also not that hard to see if you just watch a hockey game. Ericsson fought Benn. Benn still cheap-shotted Zetterberg. Downey was in the lineup when Lapierre injured Lidstrom. Lapierre didn't shy away. In fact, he came back at Downey for more in the third period, looking to crosscheck the guy in the head. Colton Orr was on the ice when Kadri was getting cheap-shotted, and eventually Kadri got into his first fight against Tampa Bay, despite Orr being out there with him. To keep the flies off. And so on, and so on.
So if you're pro-fighting, fine. I understand that it gets the heart racing, and there's a certain primitive sense of satisfaction you get when watching someone get their face beat down after wronging one of our guys. OK. I get that feeling, too, so I understand where the desire to see fights comes from (and keep in mind that I'm not at all pro-fighting. I would rather see fighting removed from the game entirely). But what I won't do is try to justify those emotions by wrongly suggesting that fighting prevents injuries from happening or keeps the rats in line. It just doesn't work that way. And its especially silly to dedicate a roster spot to an enforcer based on this false notion.