Hmmm. . . well, some wizards would be wise to do so. Even the most evil sorcerer, who did not care what his blasts of lightning and his mix-and-match monsters of lions and bears and ravens, did to the neighbors, would care what the neighbors would do to him afterward.It would be wise enough when the spell effects are not dangerous, if the spell ingredients are sufficiently noxious -- whether materially or morally. A pet basilisk is unpleasant. A grave-robber might have to venture to cities to gain his goods, but a retreat to the countryside would be necessary often enough to make it a better refuge.
A more conscientous wizard would do it for safety reasons. He would not have to worry about the morally noxious ones, but even he might have to do it for the danger.
Which would explain why one wizard of mine is found in the forest.
Except that I've already situated an entire college of wizards in the midst of a city. For good and sufficient reasons.
Hmmm. . . hmm. . . the obvious approach is that the more noxious forms of wizardry are found in isolation. A wizardling of insufficient morals could snear at another for sticking to city wizards and not venturing boldly forth to the outskirts, knowing there is more knowledge to be had there.
Except that the wizard I've stuck out in the woods is a good guy. The first other seriously good wizard that the heroine met. Hmm. . . hmm. . . he's not far from habitations. Indeed, I can put in a road in. . . and the heroine can happen on people on it, who urge her to hurry because the wizard's hours for receiving visitors are drawing to a close, which gives her a reason for hope that she will find help there. Hmmm. . .he pledged to help people as the price of the land, and he just likes his privacy -- only seriously self-absorbed extroverts find solitude always ominous.
World building can be fun.