Sorry, recently i have came across working with testers, previously i have tested website my self.
When testers do web User Interface Testing, they find silly ui bugs that users can't find and force devlopers (me) to solve those bugs.
They can't find important bugs which is related to backend programming etc.
The only bugs I would classify as "silly" are the ones that the developer should have caught himself before passing the system on to the testers, in other words, the ones that the developer should feel silly for not having spotted early on. What, exactly, do you consider to be a "silly" bug?