Just like Tyrell before him, Wallace has a massive God Complex - he even calls his replicants 'Angels'. Tyrell had managed to make both an Adam and Eve, but Wallace hasn't got the information on how to make an Eve. Once he has, he can leave the rest of humanity behind and populate the universe with his 'children', who will ostensibly be human by then but still obedient to their 'God' (who, as we saw in the scene with the newborn, is a vengeful God who rules thorugh fear). Presumably he would also then be able to clone himself (as was revealed Tyrell had done in the original screenplay for the first film in the unfilmed scene where after killing Tyrell, Roy finds the real terminally-ill Tyrell cryogenically frozen), which would then allow him to complete the transition to becoming a God by becoming immortal.
Both Wallace and the Resistance want the same thing - the ability to reproduce - but for completely opposite reasons. Wallace wants to populate the universe with a race of genetically superior but obedient superhumans. The Resistance would use it as evidence of their equality to humans (having a 'soul') in their quest to become free from slavery (from Wallace and their human masters) and become masters of their own destiny. That may result in another rebellion and war with the existing humans, which as Joshi predicts would become a slaughter due to the replicant's genetic superiority. You potentially have the same endpoint in both scenarios - '**** Replicant' becoming the new dominant species in the same way modern man wiped out the Neanderthals (Wallace's name probably wan't an accident...) with the difference being who has the power - Wallace or the replicants themselves.
