Average Joes chasing for a cheap thrill - yeah, I see where you're going with that.
But there are also many experienced and expert-class chasers, who actually know a thing or two about what they are doing. Many are meteorologists, for example; the one who died was a wind engineer... weather is a fickle beast though. Even seasoned experts get it wrong; we as a species rely heavily on computational models that also can't get it right all the time. The best chasers out there can read the atmosphere just by looking, feeling, and seeing some real-time radar and other weather data, and make some calls that decide where they need to be based on what they read says the storm will go "that way."
But we're still at the point that we can't predict weather, even down to the next minute, with 100% accuracy, especially for monumental weather events like tornadoes and other extreme atmospheric events.
The best of the best have put themselves, accidentally, in the wrong place on more than one occasion. Sometimes the timing is right and they get out of there or otherwise get lucky, but sometimes its the wrong place at the wrong time.
Regardless, don't short the chasers - we really rely on that human experience at the ground level more than you realize. They gather a ton of data and help get us, ever so slowly, to a point where we may be able to better understand these weather patterns. The experts can and have died doing this, and it's not entirely about the thrill. Sure, the ones who do it aren't being hog-tied and told they will cooperate... they usually are doing it with the reward of the thrill of the chase fully in mind, but the experts are doing it for bigger and more lasting reasons, and the thrill of the chase is simply a background element.