This is very true in my experience. Unfortunately, knowing that doesn't help when you want to go to a conference but see the plane taking off without you instea

This is very true in my experience. Unfortunately, knowing that doesn't help when you want to go to a conference but see the plane taking off without you instead. (For the record: I never had any problems whatsoever both using ESTA and a visa. However, the process feels significantly more hostile and unwelcoming compared to other countries.)