I suppose it's a matter of opinion, but if we ever wish for the slightest chance of having Scott back in STP, I think it's better that STP keep on going whether it is with Chester B or Miley Cyrus fronting them, than no STP. It seems to me that the Deleos + Kretz love nothing better than to work with each other. "Out of Time", while not exactly an amazing song in my opinion, and it may be just one song, but I think it sounds more inspired and fresh than anything off of S/T. If they'd just split, who knows if they ever bothered to come back (other than maybe to do a few big-cash shows) and that in itself (breaking up) would be a sign that they don't care enough about the band anymore. But they do. If there's someone here who thinks STP should retire and not even come back with Scott, then okay. But those who think "No STP at all unless Scott is back"; wouldn't it be a little alarming if say, Robert said he wants to go fishing to Florida for ten years. The fact that they still continue and did continue through years upon years of Scott's shenadigans (in lack of better terms) just tells us how much they love the band, want to protect it, want it to move forward - how is this any bad?
Sure it's a business too, these guys are artists but they are entrepreneurs as well. Just because a company loses a valuable part and in this case the face of the company, doesn't mean they couldn't move forward if they still can and want to.
Iron Maiden/Sabbath/Motley Crue/Van Halen all had their iconic frontmen leave at some point, only to come back later (with more or less success, but still). What all these bands did though, was to keep on going in the mean time. We all know that Scott would have to do a massive change in his ways and get his vocals back on track, for a reunion to happen. I don't see how a complete break up would better the "legacy" of STP, I see them continuing with Chester to be a better alternative than to fade away.
So, is Chester "saving" STP? I would agree with that, yes.