Currently our movie rating consists of two parts: Entertainment Rating and Technical Rating.
Let's talk about technical ratings.
Many (most?) people have used this rating value incorrectly historically. They use it as a measure of how close to optimal they think the movie is. When used this way, it is a way inflated, and mostly meaningless value. Most movies get a 7 or higher.
Simpler movies tend to get high marks because it seems clear they would be hard to improve. I rated many movies this way, and it was clear to me, this rating has almost no value.
At some point, I changed the way I rate to the original intent, which is to rate it based on how many "techniques" are demonstrated in the movie. Things such as obvious luck manipulation, route planning, use of glitches, etc. This seems like a more useful value, at first. But after rating a number of movies I found something obvious. Movies that had more aspects to it like this, I tended to like more, for obvious reasons. TASes that have a variety of TAS techniques are generally more entertaining. Go figure. So technical rating, in this context, seems to have no value either. It is just a value strongly correlated with entertainment value.
Let's talk about the cons.
1) It adds complexity and confusion to the user, making it less likely for them to participate. Participation in movie ratings is what we want most as it drives engagement and gives us values we can't do interesting things with.
2) Site complexity. We have the technical burden of maintaining the data and the code surrounding the receiving, displaying, and calculating of this value. Not to mention the performance costs of having to calculate this value frequently, and further code complexities of caching that calculation to mitigate that cost.
Given the cons and limited value of this value, it has been my conclusion for awhile now that this value should be removed, and leaving a single value that represents the overall impression by the user.