I would say this is one of the better evaluations. I'm moderately indifferent to sniping, as I'm on the consumer end. There's also something to be said for "sniping" the instant a new chapter comes out, versus "sniping" months after the release. Life happens and scanlating groups are made up of people, so some delays are inevitable, though the length here naturally raises questions. That being the case, its not uncommon for another group or individual to step in, typically because they want the story themselves and choose to share. If one chooses to complain about the quality, which is poor, though not the worst I've seen by far, that's fair. Perhaps it would be more productive to encourage rather than disparage someone who attempted to share something that EFFECTIVELY appears to have been abandoned, for reasons I at least am unaware of. But pointing a finger and screaming "sniper" because of QUALITY is laughable. Scanlating is time consuming, requires certain minimum skills, and above all else(as is constantly demonstrated) motivation. Personally, I would rather encourage someone with motivation, since skills can be taught, and the more individuals that are engaging in the process naturally leads to more available content and less delays across the medium.
If we're simply talking a matter of "courtesy"... its too often an information desert on here (not always, but often), and I wouldn't expect a clearly inexperienced person to grasp the nuance, nor in this situation (where I at least am not aware of any statements regarding the works status by the " current" group) to perhaps think it was necessary.