I have a french press and a Kuerig. The Kuerig gets used quite a bit more. I just don't have time to jack with anything slower than a Kuerig on weekdays when I'm getting ready for work.
I do like using my french presson the weekends though when I have plenty of spare time.
I don't think anyone uses a Kuerig because they think it's the best possible method of brewing a cup of coffee, it's just the most convenient/fastest/least effort by FAR.
It's basically the microwave popcorn of coffee. There's a million better & cheaper ways to make it, but none easier, and it's still quite drinkable.