And going even further, why don't customers punish the stores that give shitty customer by no longer shopping there? Same goes for your ISP, politician, etc... We have short memories.
ISPs = Not many people have a choice. My Parents can get Verizon DSL or Comcast Cable. Not really a "competitive choice".
Politicians = It takes time. Once they are elected terms last a long time and then people often have to choose a "new evil"... They can't just say welp, I don't support you anymore that'll solve the problem.