Hawkfrost: If you read more information about the series you will see that Nasu is actually a genius for creating such a large and complex universe that still manages to make sense within itself.
That's exactly along the lines of what I said; a purely conceptual element. The concept of Fate/stay Night is better than the actuality of what it is, which leads into
The big problem isn't that the writing feels stilted though, it's that huge chunks of it are boring and repetitive and pointless. Even if the prose quality were amazing that wouldn't change.
...Which is the other part of it. Pacing, along with proper sentence arrangement and flow, are essential for being a good technical writer. Failure to do so is not a subjective taste, but an inadequacy of writing ability that usually comes from either a lack of understanding of how to structure a story, or a lack of experience in executing one.
I'm not saying anything about whether the plot and world of Fate/stay is good or bad, I'm simply stating that it is some degrees of painful to read it due to how sloppy and longwinded the dialogue and exposition are. It is perfectly fine to say that you like it in spite of this, and I am not condemning fans of the series (Unlike Mahouka, which people SHOULD feel bad for liking.)