I do agree that their app works perfectly fine. And it's as responsive as HomeKit, but I don't want to have to launch 20 apps for my various devices.
In fact, after my initial irritation, I thought "at the end of the day, if they made a couple shortcuts available then I could still say <Hey Siri> Open the Garage door" – It's not perfect like homekit but it'll go a long way to placating many of us who don't want to keep launching a separate app.
I don't mind it at all. App works, fairly fast, the stupid extra stuff is just a chunk of the screen I can ignore / don't have to do / interact with.
I don't approve of the API situation but the app itself doesn't feel particularly bad.