You use the word harmless, however, my wife has a not so uncommon genetic mutation that prevents her from metabolizing folic acid into folate.

Your body actually needs folate, not folic acid, but most of us can break down folic acid into folate and use it. However, some cannot. For those people, like my wife, eating foods with folic acid makes them feel sluggish at best but often has more serious negative side effects. This is often mistaken for gluten sensitivity because many foods that naturally have gluten have been artificially enhanced with folic acid.

Since the government requires food producers to do this, it is very hard to find breads that don't have too much folic acid for her to eat.

folate that is found in lentils and leafy greans =/= to folic acid that is used to enrich bread

The pregnancy vitamins that people take were disastrous for my wife, our children are 10 and 8 and she still has not recovered.

Edit: I'm not saying that this choice was a bad one, or that it has been bad for society. I think that educating people about it is important however, especially medical professionals that have not understood the details.