Sometimes people make "bad" games because they made them to appeal to one particular crazy audience and if you don´t belong to it you will not like it in any way.
I read through germanys banned video games list and was suprised how many friggin Nazi games i found (serriously...a game called cleanse germany, Adolf Hitler or concentration camp manager (IM SERRIOUS!)is highly alerting (and mostly don´t tell what genre they are belonging to anyway)), classified as "seized nationwide" of course so i bet they run around in righty-forums pretending to not be there.
Sometimes people make bad games because THEY like them.
Sometimes the people don´t see how spastic Wiimote flailing isn´t going to sell...
Sometimes the Investors don´t want to implement some truely awesome game mechanic for fear of being too risky. (CS condition Zero was sent to GameStar, which gave it like 55% and the dev team said "It´s only a preview version, don´t sweat potential customers", and send a second copy, which sucked the same only reaching 63%, that thing went on market and sucked like you know it XD)
And yes i say "the people" constantly because game developers have the power to develop into something higher and better and become close to perfection, but fail to do so because they are opressed by some off-distant voice telling them what to do and what not, much like the rest off us.