That's a little hyperbolic. Sure, that script stops your Mac from automatically going to sleep, but it's not like it changes the CPU usage or power usage (and it will still sleep when you close the lid).

Most of the settings in that script appear to be disabling automatic or "smart" things that average users don't want to think about and power users want done a specific way (e.g. backups, screenshots). Basically if you read that script and don't understand what it's doing then you shouldn't be running it.