I know it's pedantic, but that's not true. 0.17% of people have DSPS. It's entirely possible that you don't regularly interact with anyone that has DSPS.
My point is that 0.17% is a sizable portion of the population. Your chances to encounter someone who has it are most likely higher in a thread such as this one. People click on articles they identify with. The same thing would happen if you went to a conference on the topic. I mean, there are signs of comorbidity between DSPD and depression.
Prevalence 7% to 16% in teenagers and young adults, that's 7 in 100 to 4 in 25. Data from 2002, Source: Ando K, Kripke DF, Ancoli-Israel S. Delayed and advanced sleep phase symptoms. Isr J Psychiatry Relat Sci. 2002; 39(1): 11–18.
Please always provide citations and indicate whether you refer to incidence or prevalence; and to which bin you refer to, even if you refer to some global bin.
I'd provide newer & more data, but I'm on mobile right now.