No, it´s more those shameless teenagers, who are putting themselves out there. And it´s not Poirot, who does the ranting, it´s more the other characters in the book. It´s just odd and not fitting for the story.
LOL sorry that must be just a USA thing. You know every generation of old farts complains about the youngsters. So for the last few years, there have been articles upon articles blaming the current young adult generation (called Millennials for people born 1981-1996 and reaching adulthood at the turn of the century) for the death of various industries with their spending habits. Somehow "avocado toast" became the joke/meme for all these Boomer complaints about the Millennial generation.
See https://www.brandwatch.com/blog/react-millennials-are-killing-2019/
and https://www.cbinsights.com/research/millennials-killing-industries/