Sure but once we are in this subjective area, it becomes very hard to really make any worthwhile factual arguments. Like I mentioned way before it becomes an arena of personal taste and opinion. I completely disagree that it is automatically easier, because when it comes to critical acclaim, you will find that flawed "ambitious" stories are generally more well liked or get more attention than well executed short stories. It is definitely easier to get people to grow attached to characters and story hooks in a long-form story simply because of how much space you have to let things breath. It is harder to achieve the same result in shorter or episodic tales, and hence there is a different sort of challenge there.
I feel that you are biased against one form of storytelling, and hence your comparisons to what makes one harder or the other easier is based on narrative requirements which favor long-form stories, instead of opening your mind to see that short-form stories have a different set of equally challenging conditions which don't generally apply to long-form stories.