This is a wise move. I think it’s likely that Ethereum will suffer from some nasty security vulnerabilities as we move forward, given its added complexity. One of the huge advantages Bitcoin will have with a system like RootStock is that it is a clear separation of concerns. If the RootStock software or blockchain suffers an attack, it will not affect Bitcoin at all. However with Ethereum, it will bring the ENTIRE ecosystem to its knees. Very worrying.