I think that its all about context. I dont think its unreasonable for a judge to dock points from a level if a certain aspect of it can be fundamentally broken by an oversight. I think it's up to the designer to try to accommodate for as many possible exploits as possible, and just blaming the player for trying it seems kind of unproductive.
There's a distinct difference between duplicating a block, throwing away an item, and just scrolling the screen. Duplicating a block to get an item that lets you bypass a level should never be considered in a level's score, as it's an unintended method of playing the game that the player knows is actively breaking the internal rules. Throwing an item down a pit accidentally, or deliberately, doesnt fall on the fault of the designer (most of the time) as it's reasonable to expect the player will not do such a counter-productive action.
Scrolling the screen however, is a part of the base game and built into the internal rules. And as such, it is perfectly reasonable to be expected to be able to design a level with it in mind; obviously in most cases we have the power to disable scrolling with uberasm, but without it it's up to you to keep it in mind when making your level.
I think it's on the same level of complaining that pressing select with a reserve item is cheating because you're supposed to do that section small. Or even getting mad at a player for spin jumping off of a thwomp instead of jumping over it. If it's a part of the base game's rules, it need to be accounted for.
But that's just my opinion
ask me if i give a f*ck...