Internal martial arts: a fiction?

[Crosshandz]

I have been practicing Kung fu on and off for a number of years. In that time I have had the honour of taking classes from some pretty good martial artists and I am increasingly persuaded that the paradigm "internal" martial arts is a fiction.

After all these years observing martial arts I find it difficult to explain how Hung Gar is "external" and Xingyi is "internal", for example. As far as I can see barring some differences in method of power development and some in some methods of power exertion there isn't a paper width of difference between "internal" and "external" in practice. Someone hitting you with Taiji short power, to me, seems very similar to someone hitting you with Southern Mantis short power.

Yet I have witnessed heated arguments between "internal" and "external" stylists about the wrong power/energy/body method being used in techniques so I am curious to know what is it I am missing if anything?