It happens because people will go to great lengths to ski great untouched terrain. You have to be smart and know the avalanche report so you make decisions that won't put you in (too much) danger. But, honestly, sometimes nature does what it wants. Even extremely experienced people end up dying (see background and some pretty kickass footage from a guy who dies earlier this year near CB)
https://www.gunnisontimes.com/articles/eric-freson/
Eric enjoyed skiing, snowmobiling and ice climbing in the winter months. He combined all three passions frequently in pursuit of placing turns at obscure places and times. Eric rallied his friends to start skiing at night to get more hours in during the day. Nighttime second bowl laps became a weekly occurrence. His ski equipment frequently included ropes, crampons, ice axes, and deep trust between partners as essential tools for skiing the lines he was interested in. Eric would patiently scout lines, sometimes for multiple seasons, until conditions aligned, but would also be up for a quick strike mission when the snow was good. For Eric, the people and the places were just as important as the snow conditions to have a good ski day.