In my personal opinion, a group of individuals can actually maintain a certain quality of language and usage. My thought behind this is if the group is willing to put in effort and backs up that effort through continous practice, then technically you could maintain the quailty. As long as they continuously use a particular level of vocabulary, grammar and pronunciation. The only way that would make it fall apart is if it isn't taken care of, the group members decide to give up on trying. My opinion on what constitutes good and bad is the usage of slang words such as typing "u" instead of "you" and so on. I think it would be necessary for speakers and writers to follow a particular standard of correctness so we can all understand eachother. I think that with the situation it could fluctuate as well as the audience but I'd even think the audience should follow a standard.
