That "glue is stronger than wood" saying is mostly true. What is meant by that is that wood glue is a stronger binder than the stuff that binds wood fibers together naturally (lignen). However, under bending stress, the strength of wood glue is far inferior to the strength of wood grain. This is where the "don't glue end grains together" myth comes from. End grain joints are fine, but if you expect them to perform like an unbroken fiber, you'll be dissapointed.