There's a good chance this is true, but this can happen even with competent developers. One person writes the unoptimized function figuring it can be improved l

There's a good chance this is true, but this can happen even with competent developers. One person writes the unoptimized function figuring it can be improved later, someone else assumes this must be cheap and drops it on the front page. Or there was meant to be a caching layer, that didn't work because of some bug.