It was the next day. They were in orbit. They would have had to come back through the atmosphere to land - or do you know of some back door from space to Kennedy?
1. They didn't "have" a problem until the next day. There was no basis on which to call an abort.
2. The Flight Rules governing an abort are very specific, and very limited. They are not based on "something that we won't even know about until tomorrow may have happened (or not)." (Having participated in meetings where these rules were reviewed and revised post-Challenger, I know this to be true.)
3. Aborts are dangerous. The probability of the Shuttle surviving an abort is significantly less than one -- and thus they are (again) not something to do on the basis of "bad feelings." In any case that does not involve serious propulsion or guidance problems, orbit is the safest place to go.