Loading times surely is not a problem unique to Powershell. The more complex and advanced a software gets, the more it takes to load data into RAM that appears to the user redundant.

This is the most noticable with startup times. My favorite software (Firefox) has this solved; it opens up in reasonable amounts of time, even if it takes a moment after to show the first website. My second favorite software (Inkscape), meanwhile, takes so long just to show the main UI that the developers didn't think anything of adding a splash screen: an overt acknowledgement that you're keeping the user waiting.

I, too, wish that everything were more lean and snappy, but clearly this is still an unsolved problem.