As a married guy I find this line of thinking hard to understand. “How are we supposed to work so closely with these people without getting ‘too close?’” Uh, I’m not allowed to solicit a date in any context: work, the grocery store, cafes, etc. Somehow I manage, and so do most married people.
As a married guy, if your marriage is truly fulfilling, this problem is irrelevant to you.
Given that proximity is the single largest determining factor in romantic partnership, if you work the majority of your time then coworkers will be your most promising dating pool. If you don't work much, you're probably stressed from unemployment. The number of people that have free time to enjoy close proximity with non-coworkers is certainly a minority.
It's not that point I read from the parent. It's that they're prime candidates so it's unfortunate to waste that connection. Not that it in any way is hard to resist urges.