He who makes no mistakes makes nothing. A student should be allowed the time to make a few mistakes whilst under supervision. If that means allowing a little more altitude "for the wife and kids" then so be it. As already mentioned, the stall should not be taught as a standalone package but should build on other skills already taught, therefore the climb to a safe altitude can be used to good effect. Remembering that the job of a good instructor is to show the student as many pitfalls as possible as he may not live long enough to make them all himself