I think that only teaching one sort is crippling. Remember that Everything Is Fast For Small n, so in terms of teaching a sort, it is not a question of performance, but understanding the algorithm.
I think the intro should be the bubble sort to introduce the concept, but at a minimum introduce another sort to get the students thinking about other ways to perform the task. Make sure they understand the tradeoff in performance and code complexity and that there are different tools for different situations.
