There is a difference between giving credit to people who happen to believe in teleology and giving credit to teleology itself.
The fundamental problem with ID is that it is primarily a political movement and secondarily religious apologetics. The scientific content - such as there is - exists only to support the real objectives.
Would it harm science to misrepresent it in classrooms ? I say it would.
Would it harm science if it were to be twisted into "supporting" theological conclusions. Of course it would.
But that is what the ID movement wants. ID definitely would harm science.