I'm aware that I can buy a separate remote - and the model you highlighted is a good one - I just wonder why I should have to. And Roku won't even sell a backlit remote as an accessory.
In my experience, when companies don't do something that they easily could do and for which customers are clamoring, there's almost always a reason. People have been bugging Roku for a backlit remote for years. There's some reason why they're not doing it.
The Roku app has a competent remote, although not as fully featured as the physical remote.