I think a common approach is “I know this job is garbage but if I can last 18 months, my resume will look much better”.....or.....”maybe my manager will be alright and the bad stories will be less relevant”
Another factor might be that there are many companies just as bad, but without the prestige of Amazon. At least the Amazon name will pad your resume. The names of many other bad companies won't (or not to the degree of Amazon).