Gregory's Server
The "multiverse" of star systems that solves the rare earth problem is scientific / we can create a model of stellar evolution and evaluate it against competing models, say Giordano Bruno's / we can experimentally confirm or falsify the model using telescopes / whereas multiverse anthropics adopts an idea based entirely on how convenient it would be for academics if it were true / and then imagines it can be used to solve real-world questions
That the string theorists got so lost in their own thoughts so quickly should serve as a warning / if a multiverse is to be considered at all the concept needs to be used in as limited a way as possible with as few assumptions as possible / hence to me the attraction of the Tegmark multiverse, if any / the simplest possible hypothesis with the largest possible ensemble / literally every conceivable universe with systemic behavior included by definition