Why?
1. I don't agree with Samsung's business ethics. They hire students to bash the HTC One on message boards. (documented) Yeah, they publicly apologized for "insufficient training" of the people who hired the students. Big deal. The product launch for the GS4 was horrible sexist. I don't want to contribute any money towards that kind of stuff. Their whole aura leaves a bad tasted in my mouth.
2. Samsung product support sucks. I have a bunch of Samsung electronics-- tablet, wifi camera, phone, etc. I don't know where they get their support people, but they are rude, condescending, and mostly have very little knowledge of the product. Their product manuals are horribly incomplete, which makes it necessary to contact support at times.
3. The Gs4 looks like it could be a vintage phone, 60's style. The design goes right along with their attitudes towards women. They are about 50 years behind. The phone is just not....modern. It has a very cheap feel, and has lag problems, according to the Gs4 board. The vaunted new air stuff and smart stay doesn't work consistently, and I probably wouldn't use those anyway. I see on the Gs4 board that the air hover feature causes arm fatigue. The display has "green color" problems.
4. On the other hand, my HtC One is perfect. I have run into no problems. I like the camera. I love the sequence shot, I love the highlight videos, I love the display. I have never had a bit of lag. I love blink feed. It actually makes the smartphone experience interesting. I do have Flipbook as well, but I like blinkfeed better, it has a smoother operation. Audio quality is very important to me, and the call quality is excellent. Just an all-around great phone for me.