One point is that the Parker and Cross type of refills completely replaces the writing head and so by one view it is not really “BIFL” since so much of the unit has to be refreshed (and so not as environmentally friendly) compared to a fountain pen. That being said, for some people the risk of ink all over your hands is not worth or even entirely precludes using a fountain pen, or there may be other circumstances.

For example, at my workplace there is only one approved type of pen that can be used 😢