A lot of Russian design philosophy is based on the old KISS principle: keep it simple, stupid.
When Russian makes good stuff it's because it excels at being rugged, and simple to maintain. It's not going to have Star Wars avionics and fire control. But then again when fighting goat humpers, do you need Buck Rogers?
And considering goat humpers are doing the maintenance, KISS is a good way to go. I wouldn't be surprised if the US product also comes with American maintenance contractors, with taxpayers picking up the tab.
And seriously, if your helicopters can't do altitude in Afghanistan, you are already in trouble.
It has been said that Russian is a great language for paranoids. If you are paranoid, you don’t care much for creature comforts, or bells and whistles. You want weapons that are rugged, reliable, and that can be produced in large quantities. Add in the fact that the Russian military is largely made up of poorly educated conscripts and the KISS principle becomes not just desirable but essential.