So you just admitted that the BU is just about block size increase for now  

You didn't answer on technical problematics : _What about the total blockchain size which will grow exponentially faster with a block size increase ?
                                                              _What will be the block size with BU ? By choice of miners ? So the security problems and immutability problems that will result ?
                                                              _I'm not saying that segwit is essential, i think it's the best solution for now but of courseall solutions could always be better   but if segwit will be rejected well i wouldn't think bitcoin is dead but if the chain split or if BU become the established chain i would reconsider my position on mid-term long-term investments due to the problematics that will cause