这是一个人说的话，发生了口误。这个句子有二处语法错误。第一，whereas是个连词，引导对比状语从句，而这个句子却仅仅是whereas引导的从句。第二，when是多余的，应该删去。口语中出现语法错误是不奇怪的。

正确的句子应该如下：

Whereas a few years ago, the kids were all out binge drinking, nobody wants that any more now—everybody wants to portray this amazing, perfect life.