Although it's not written into the regulations, it will be written into most flying school's operations manual.
As Captain Nomad said there have been numerous occassions where stalls are being practiced, particularly stalls in the approach configuration, where a student does not react properly and a. loses a fair bit of altitude, or b. puts the aircraft into a spin.
To claim that the extra climb is used to make more money is rubbish. If anything it gives the student pilot a chance to practice climbing again, which they would have learned properly only two lessons prior.