Earlier quoted context omitted.
The issue is partially that pregnant women don't drink (and disclosing pregnancy shouldn't be part of the job interview), and partially that bars can be uncomfortable places for women. A woman should not have to worry about the guy one table over eying her up while she's trying to land a job. Bars are casual places, and it's not wrong to check someone out or hit on them. Indeed, that's one of the reasons people go to…
Wouldn't that depend on the choice of bar? There's a big difference between a nightclub at midnight and a gastropub during lunch time, especially since the latter will tend to also serve a selection of non alcoholic drinks. People checking you out would also be a problem you could just as easily encounter at starbucks or indeed in the office.
And yes, you can encounter unwanted attention anywhere, but at a bar at night, certain sorts of advances are acceptable and expected. Indeed, I'd raise an eyebrow if someone complained about getting unwanted but otherwise harmless attention at a bar. Those advances aren't what is inappropriate--it's holding a job interview in that setting that's inappropriate.