I think what you're seeing isn't a problem in how we play so much as it is a problem I've been noticing in the dissemination of Mafia theory. The vast majority of experienced players do not consider trying to not die to be inherently scummy. Rather, the idea is that if a player appears to be prioritizing their survival over the interests of the town in such a way that the latter is harmed, that is an indication that said player may not be town. (And yes, we recognize that trying to survive as town is generally in the interests of the town.) Like every other thing about Mafia, context (such as player inexperience) absolutely must be taken into account in determining both whether the apparent priorities were real and whether the player is non-town, and experienced players take context into account.
The problem comes from how the idea is disseminated. There is a trend, in and out of Mafia, towards trying to summarize every idea, no matter how complex, in pithy slogans and soundbites. In Mafia, these incomplete summaries tend to be aggressively exaggerated, fitting with our aggressive use and manipulation of language. What we end up with are catchy and exaggerated summaries of parts of our ideas that we use to represent the ideas themselves.
Unfortunately, while people know the ideas and act based on the ideas, people generally speak in the catchy and exaggerated summaries. Newbies then come in, see the summaries, and, having no reason not to do so, come to believe that those are the ideas. The summaries are disseminated far more effectively than the ideas they represent, and this is quite harmful. It causes communication failures between experienced players and newbies, nervousness among newbies, and some poor or terrible cases, along with many other problems.
I think online Mafia players, in and out of Bay 12, need to stay aware of the pithy summary issue and try to avoid continuing distortion of Mafia theory.
There are certain times when this is true, but by performing any action (like perceived bandwagoning) that could be seen as scummy often leads to a mislynch of them, which they also don't want.
Outside of day 1 and BMs, more evidence than that is almost always necessary. Players aren't quite that incompetent.
For example, what if someone delivered the hammer vote (in a game with hammers) on what they believed were excellent grounds, but were judged later as being faulty and misguided. That player is going to have a hell of a time not being lynched as an overeager scum, particularly if they are perceived as new or inexperienced (even though they might have a firm grasp on the game). I say particularly for those perceived as new or inexperienced because it is easy to jump to the conclusion that "oh, yeah, their just being a silly newb scum", whereas someone deemed "experienced" will often at least be given a fair hearing.
I disagree with your point here. Newbies tend to get far more leeway in acting like that than experienced players. Good example: CYOM, where we largely ignored the inexperienced Day 1 hammerer even after a ridiculously poor hammer.