All knowledge must come before the court of language and be judged.It has, but this isn't the court of language for physics or math words. What do you know about compact spaces? It's the people who use the word who accept it or discard it, and they have accepted compactify to mean make compact. To me, to compact (verb) means to squish, which isn't very mathematical, and isn't quite what they mean. So they need to use compactify. And when you make it into a past tense, it becomes compactified.
Most standard scientific words, even simple ones, are not in a typical dictionary. For example, in math and science, linearize = to make linear. And I don't mean "make straight" or "straighten out" because linear has a precise definition. You don't want to lose that definition when you turn it into a verb, so linear has to be the base of the verb, and you have linearize.
I have tons of other examples which are possibly awkward but are the most
compact 
way of expressing something: radially (in a radial direction, that is, outward or inward from the centre, as opposed to tangentially), dimensionalize (to make a set of equations dimensional), upwelling (the welling up of water from lower depths to shallower depths), compositing (to make a composite data set), convecting (the act of convection), advecting (the act of advection), insolation (amount of solar radiation)...the list of non-recognized words goes on and on. (This was just from a quick spell-check of my last few term papers.)
If everyone in the field uses these words in a certain accepted pattern, with conjugations and pluralizations that are tacitly agreed upon, that makes them words, in much the same way as any other word becomes accepted as a word!
