You clearly have limited view on application bugs. Let me elaborate a bit on bugs causing application dissatisfaction and UX frustration without crashing much, much worse than a simple error message along the lines: "OS has terminated application X because it has performed an illegal operation."

Data corruption - reading or writing corrupted data - files cannot be read, saved files get corrupted, API calls from/to external applications/systems fail or pass incorrect data Rendering problems - corrupted images, incorrect colors, improper content encoding, visual stuttering, audio deformation, audio skipping Input/output lags - unregistered kaystrokes, missed actions and responses to external events, mouse stuttering and misbehavior Improper operation - inconsistent results - repeated rendering yields different results (html), formulas/calculation results in data is inconsistent (excel, DWH) Access violation - access gained to invalid or protected areas - unprivileged access, license violations, access to areas protected by AAA, data theft (SQL injection, database dumps)

and others. If I figure out the application I'm using (web-browser) allowed a hacker to steal my data he would not have otherwise access to I would be more pissed off than if it crashed and I found an error about it in system log.