Memes are subject to evolution. I would expect that fanatics are selected, to a certain extent, for fanaticism that happens to work in a way conducive to spreading the fanaticism. So it's not really inconsistent to point out that they have standard goals such as religious fanaticism and lust for power, yet to note that they do "rational things". After all, any group of fanatics who want power, but act in ways that are sufficiently irrational as to be ineffective, never would have become known except as a historical footnote.

(Note that this doesn't mean that every single thing they do is "rational", just a couple of the top ones. It is consistent that ISIS makes people skeptical of Islam and prevents Islam from spreading to Europe, because other groups are also ineffective at spreading Islam to Europe and not being very good at it either doesn't put ISIS at much of a competitive disadvantage.)