About 24 years ago I built a webmail service based on C++ cgi's. FastCGI existed, but that required perfect memory management. CGI let us do what your instructor did, and on one hand it saved us from dealing with leaks at all, and on the other it reduced the performance overhead of going for CGIs - much faster to deallocate the whole heap in one go.

We'd manually deallocate particularly big allocations, but otherwise we knew the process would die within fractions of a second anyway, so the increased memory use was fairly limited.

We served a couple of million users with that using servers with a combined capacity lower than my current desktop.