Users don&#x27;t always use all of their apps apps every day. If you go to the app 20 days after updating the OS, good luck remembering the OS update 3 weeks ago and deducing it was that which broke it.<p>Especially since, with the ability for apps to upgrade automatically, many don&#x27;t even keep track when this or that app was updated.<p>Of course it usually is even more obscure, e.g. the bug only affects PART of the app&#x27;s functionality, a part which you might have not invoked in your last run before the OS update. So, another deduction for many would be that that feature works intermittently because it&#x27;s not coded well, etc.<p>Besides, even when the user can deduce that the OS broke the app, they don&#x27;t complain to Apple, but to the software maker &quot;fix your app&quot;, &quot;where&#x27;s the update release?&quot;, etc.