The "rule" about split infinitives was never a rule of the language, it was, and is, and always has been a phony "rule" made up by relatively linguistically ignorant "grammarians" whose notion of "grammar" equated with "latin" in which a split infinitive is an impossibility. English is not, however, an inflective language but a distributive one, in which the only sin in splitting an infinitive is introducing ambiguity. And the sin there is in the ambiguity, not thte split infinitive. Self-consciously unsplit infinitives are far worse than unambiguous split ones. They sound funny. Has nothing to do with "breaking a rule often enough" - that notion just demonstrates unawareness of the fact that languages have their own rules, by which they always operate, and which people can't break. Language is an organic phenomenon of the human psyche, it is not something the human mind designed to follow "rules."