Re: are surprised it bends / cracks - really.
Yes, many people are. Sometimes even my roomie who posses an Engineering degree and makes things that must withstand far greater stresses.
Also the definition of "a lot of force" is too flexible. The actual analysis is more complicated:
1. Is the method of carrying it an expected mode of transport for the typical user?
2. Is the answer to 1 is yes, did you account for this in the design?
3. If it was accounted for in the design was it tested in QA?
Fail any of those in the US and you have a potential class action lawsuit. Yes, it is as silly as the warnings on step ladders that you shouldn't attempt to stand on the piece that is intended to hold a pain can, but that is the precedent I am referencing.