I don't let things cloud my judgment that easily. Chara made a hit that's been made countless times. This time, and on a few other occasions, it turned out very badly.
This is an issue on the structure of Rinks, not on Intent of the Player.
Why should he have been Suspended?
because he made a careless play in violation of standard accepted game rules. it was an interference, made with a combination of carelessness (position and timing) and force (its clear that he did not slow down, let up, or hold back on the hit in any noticeable way) that resulted in a horrible player injury
society has a number of laws and penalties to deal with unfortunate accidents that may be deemed a result of carelessness. these exist (and are [at least, at times] enforced) in order to make the point that being careless can have very, very negative consequences and that it should not be tolerated or accepted as general practice.
doing nothing shows that carelessness (in particular, carelessness that is also part of an infraction) is acceptable, whatever the result.
im not saying kick him out of the nhl, but something other than "oops" would be appropriate in order to show that some level of "we give a shit" is held by chara and the league.
as it is, it pretty much looks like the nhl doesnt really give a flying fuck that pacioretty was seriously injured due to a poorly timed, very careless play (made in direct violation of a well known rule of the game), and thats a terrible stance to take in my opinion (and clearly the opinion of many others)