As a frequent international and domestic business traveler, since the inception of TSA never once have I lost an item, or had an issue. It's comical to watch "amateurs" go through screening and make fools of themselves challenging TSA.
They have a job to do (whether it keeps us safe or not) and extending patience and simple common courtesy to them makes the whole process flow properly. The TSA staff you come in contact with at the entry points DOES NOT set policy, they just implement as directed.
Proper packing, including as previously mentioned, keeping your valuables together, waiting for your carry on's to go through the scanner prior to you being scanned all go a long way towards making the process quick and easy.
Traveling with an expandable carry on helps avoid issues with checked bags. Learn how to pack. (I've traveled 10 days with just a carry on...) Oh, and just because you're late to the airport for your flight doesn't give you any priority in line, or with the TSA staff "hurrying you through."