I believe people are certainly biased towards sports that they enjoy and support and want to think the best of them, however if we're looking at a purely objective view I don't know how you can say with a straight face that hockey is very bad at all when it comes to the problems it has.
I think at the lower levels of hockey there seems to be more issues, but once players get to the NHL it definitely looks like there are very few players who are truly bad enough to commit serious crimes. I mean outside of this case where the players involved weren't yet in the NHL, how many NHL players do you remember committing serious crime or violence over the years where they ended up getting charged/arrested/going to jail? Extremely few.
On the otherhand look at the list of NFL players who have been involved in both minor and major crimes in just the past few years:
These are arrests, charges and citations of NFL players for crimes more serious than common traffic violations. Almost all of the players belonged to an NFL roster at the time of the incident. In rare cases, a free agent is included only if that player later signs with an NFL team. The data...
databases.usatoday.com
That's a pretty crazy large list of players getting in trouble don't you think? Can you imagine the amount of outrage if we saw a list this large for NHL players getting in trouble? It would be insane and yet without looking it up I didn't know that THIS many NFL players have been getting into trouble because its so rarely talked about in the media anywhere. Heck I've seen 1000x more coverage about Taylor Swift going to KC games than I've ever heard of any NFL players getting into trouble this year.
I'm not saying hockey or the NHL doesn't have its problems, but compared to other leagues its doing pretty well especially if we're talking about players who reach the NHL and how relatively little serious trouble they get into. I think this is a case where the fact that something happens so rarely, it will undoubtedly get more attention when something serious does happen.
It would be like you hearing about a shooting in a US city and thinking 'Here we go again, so what else is new?' compared to hearing about a shooting in Tokyo and thinking 'Wow! That's crazy!' because such incidents are so rare in Japan. I think the same applies to the NHL where incidents are so rare that when something major does happen some people go overboard with the criticism and believing these incidents are a regular occurrence among hockey players rather than looking at the facts and realize that these incidents are pretty uncommon especially among NHL players.