I think that the "concern" is grossly overblown, not by those who sought charges, but by those who want to assert that the prosecution's hand was forced by "outside pressure." Indeed, if he were not charged but for the outside pressure, I am in favor of it. The short form response is a young man is dead and it is important that the cause of his death and appropriate response to it be determined through the judicaial process. I have seen no evidence that the judicial process is in any way tainted by outside pressure, and none has been presented here. The usual partisan tropes have been asserted, and the typical baseless whines voiced. The judge appeared to have handled the arraignment by the book, granted reasonable bail based upon the circumstances presented to him, and got appropriately pissed when he found that he was purposely misled. Charges against Mrs. Zimmerman seem appropriate based upon the couples' coordinated efforts - which is the subject of this thread - and it is likely that it will have an impact on the presentation of his case (as well as the probability of additional, unrelated charges).
As I noted before, there has not been an unrelenting "rush to judgment" here, it was just an interesting twist that is likely to have some impact on the presentation of the case, and demonstrates, to some degree, a character trait that is unflattering. Either there will be a trial or there will not (likely because of a plea deal), and there will either be a conviction, or there won't. Only time, and the appropriate judicial processes, will tell. From a professional standpoint, I do not believe that the 2nd degree murder charge is inappropriate to the facts of the Information. It is not overcharging, as a manslaughter charge does not fit the known circumstances.
A well reasoned argument is like a diamond: impervious to corruption and crystal clear - and infinitely rarer.
Here, as elsewhere, people are outraged at what feels like a rigged game -- an economy that won't respond, a democracy that won't listen, and a financial sector that holds all the cards. - Robert Reich