While traders using stop loss are very very common(understandably so), some people simply doesn't like using it simply because it doesn't apply to their sort of 'style'. Always remember that trading strategies are going to vary from person to person.
Style of trading you said? No kind of styles in trading that wouldn't work with stop loss, many people are really not seeing the importance of stop loss till something bad happens, am talking from experience am a victim of same circumstances, I believed am good at what am doing, managed my risk well and got enough equity to withhold any dip so no need for stop-loss, but a day came where the market crashed and everything tradeable was badly bleeding and I got rekt, I learned my lesson the hard way.