Some Gen Z customers are outraged at Chipotle's seemingly shrinking portion sizes while profits soar to record highs.In early May, TikTok food influencer Keith Lee posted a review of Chipotle Mexican Grill (CMG 0.43%). The creator, who boasts more than 16 million subscribers, called the restaurant's portions "crazy" and rated its chicken al-pastor and rice bowl a 2 out of 10. His remarks may have helped start a trend called the "walkout method," where customers simply leave Chipotle restaurants mid-order if ...