I understand why you're saying that but when you try do develop on Xcode running an emulator and at the same try to use your machine normally (keeping some tabs

I understand why you're saying that but when you try do develop on Xcode running an emulator and at the same try to use your machine normally (keeping some tabs open, listening to some music etc.), suddenly 8 GB seems like very little. Moreover, when you develop for a platform like iOS, you have very limited control on how fat your application will be.