"In Latin, it is not possible to split an infinitive. So in English, the early authorities decided, it should not be possible to split an infinitive either. But there is no reason why we shouldn't, any more that we should forsake instant coffee and air travel because they weren't available to the Romans. ...Nothing illustrates the scope for prejudice in English better than the issue of the split infinitive. Some people feel ridiculously strongly about it. When the British Conservative politician Jock Bruce-Gardyne was economic secretary to the Treasury in the early 1980s, he returned unread any departmental correspondence containing a split infinitive. (It should perhaps be pointed out that a split infinitive is one in which an adverb comes between to and a verb, as in to quickly look .) I can think of two very good reasons for not splitting an infinitive.--The Mother Tongue: English and How it Got That Way by Bill Bryson
1.) Because you feel that the rules of English ought to conform to the grammatical precepts of a language that died a thousand years ago.
2.) Because you wish to cling to a pointless affectation of usage that is without the support of any recognized authority of the last 200 years, even at the cost of composing sentences that are ambiguous, inelegant, and patently contorted. "