Because it is required to be a genius to cap cheats untill certain events are over. If event X procs with 50 points of popularity, cap cheats to 50 points until the event is over. Nah, better let's blame users for devs being retarded.
If a cheat is done for special testing purposes and certain values cannot exist at the time watched, there is no need to insert restrictions or caps. Which can mean that either devs do not care or will not find out that this "problem" exists because they do not screw it up. Have you ever written a more complex program than "Hello World" yourself? Especially in the "Post Basic" era?
And cheats shouldn't be made for players because...?
(a) ... because a dev does not think that is the way he wants the game to be played
(b) ... because creating cheats, especially making them "foolproof", takes away time better spent elsewhere
(c) ... because creating a foolproof system does not work and a dev does not want their game to appear to be crashing continuously
(d) ... because of any other reason a dev can think of not to want to do that
(e) ... any combination of the above.
Of course a dev can still decide to include cheat options, and quite a few do, with all possible caveats. But it is not as if players were somehow entitled to getting some system just because they want to.