There are perfectly legitimate uses of a colon after an incomplete sentence and they are not abominable or even mildly unpleasant.

A colon can be used to separate a dependent word or word group from an independent one - Warning: do not go beyond this point.

A colon can be used before a significant one-sentence quotation or a quotation made up of more than one sentence - Jane Austen said: "One half of the world cannot understand the pleasures of the other half"

A colon can be used between speaker identification and speech in a text such as a play or between a title and a subtitle.

There must be other possibilities.