Powershell's single, deal-breaking problem is that there is no integration with the rich Unix CLI environment, which means that it can hardly be used as the superglue that bash and zsh can be used for. Which means that it's basically a shell language on steroids, for which I'd much rather recommend and interactive Ruby or Python shell. Powershell's problem is that it exists in an ecosystem that does not acknowledge the CLI, and it will not be useful until that situation is reversed. Since, to this day, mos windows apps don't have backends for CLI interaction, I doubt thethings will change for several years.