Though a part of the article and other studies address that to an extent:

The median age for first marriage in America is now 29 for men and 27 for women, up from 27 and 25 in 1999. While young people are often more likely to live together than their forbears, the number of cohabiting 20-somethings has remained constant, while the number of 20-something spouses has dropped. And increasingly, young people are eschewing having a relationship with one partner and instead hanging out with a loosely assorted group of friends. So there’s just less of that convenience sex going on. “When people are young and healthy and have the highest sex drive, they are less likely to be living with a partner,” says Twenge. “So there’s a larger proportion of people in their early 20s who are not having sex at all.” This is not just in the U.S. Brits are delaying even longer. More than 40% of Japanese 18- to 34-year-old singles claim they are virgins.

It does appear that there is a rise in STD rates of late (the recent increase appears to be happening more recently than the poster's time in the Urgent Care, but is still a good point) due to a variety of factors:

Why? The CDC cites numerous potential reasons, including poverty, drug use, decreases in condom use, and stigma surrounding STDs. Add to that recent cuts to state and local STD programs, resulting in clinic closures and less screening and patient follow-up.

Many experts believe funding cuts are a critical factor, according to Fred Wyand, communications director for the nonprofit American Sexual Health Association.

"The subject of STD rates and why they remain so high is a discussion with much nuance and no single, simple answer," Wyand noted. "But the public health experts who advise us consistently refer to an eroding STD prevention infrastructure as a key element in driving STD rates."

It's all very interesting trends to notice.  Even more interesting will be getting to the "whys".