So? Unless the students where kids (as opposed to 18 and above), that's a moralist, religious-derived, US-centric concern (not that such moralism hasn't made its way and infected other parts of the world)...
People that call out adults for sleeping with whoever adult they like are worse than people that sleep with their adult students...
It's a conflict of interest, like an employee sleeping with their boss. It's hard to trust somebody to fairly assess somebody they're sleeping with.
It's only bad if it's part of blackmail or exchange (e.g. for grades, etc). Else, if it's a consentual relation, it's fine just like any other.
Lots of employees have had great relationships and marriages and kids with their bosses and vice versa. And even more students and professors had affairs (this will include someone like French President Macron). Humans are humans they don't easily compartmentalize their attraction or sexuality just because some bureaucratic rules say so.
This is exactly my point. Even if the professor and student don't intend it to be a grades-for-sex exchange, it would be hard for the professor to be completely objective, and not unfairly grade that student higher than other students with whom the professor didn't have such a close relationship.
That it's not generally a good idea is inherent in the "sometime it doesn't work out well" (the complamentary to "it sometimes works out well"). But that's also true for most affairs/relationships, and according to statistics, marriages (if we consider a divorce as "the marriage not working out well"). And it can be awkward, like those.
But my point was, it's human, and not some moral issue to condemn a person or a writer's writing for.
> moralist, religious-derived, US-centric concern
Then again, if teacher touches you inappropriately in US or is trying to manipulate you into that, you can actually complain. It is not easy and you may not be believed, but you are is still in better compared to less moralist places.
It is not exactly US-centric concern to think that any of above happen. The same happen everywhere. It is that complaining about it in US is not a taboo.
I think it's more that sexuality in the US is a taboo, and everything is seen in the prism of violation and litigation.
Non american women do get touched inappropriately and they do not like it. And they do complain about it, if you know them close enough.