MS has made a lot of positive steps over time, though the MS store still leaves a lot to be desired in my book. The store user experience still needs work, it is far from my first choice for buying games.
I agree that it is good that it exists and that it gets the job done alright, but that doesn't mean that Microsoft shouldn't strive to do better. It takes more than a few clicks to navigate to my full games list for example, something that really should be better if MS wants to be taken seriously by PC gamers.