And I'll probably get attacked for this completely reasonable post.
I hope not. Reasonable comments should be met in a mutual manner

I do disagree on parts or have comments on parts of what you said, so if you don't mind I'd like to share them.
1) You're right, in time they do add up. However, it does with Netflix as well, and with Netflix you can only watch what others have made. With MS you can be the director, so if you're the creative type that $8.00 has a greater inherent value.
2) I had the same concern when the subscription model first came out, but my opinion changed. Look at it this way...if you made a real movie and rented a studio, props, wardrobe, etc. and hired actors, you don't own any of it. But you would own what you made with it.
With MS you own content you buy. What you rent is the core program. I know the main sticking point there is owning content but not being able to use it without subscribing. That is precisely why MS created the option to purchase the program. Renting is not the only option, and honestly, the cost of buying the program and all the content is much cheaper then getting the same amount from iClone, and the learning curve is much better (and potential aside, overall I've seen better results with MS).
3) I had the same opinion at first. According to Matt and other staffers, the reason it is this way is because of funding development. The rental fee funds development, sales of content funds content development.
MS was never meant to be a hobby for the people making it. It's always been a business. There are a lot of talented people involved in making it, and they do so to make their own living. If no one pays for the product, no one gets paid to develop it, and there is no product. So if they don't make money on content, should they use rental fees for developing content and the core program? I can't help but think both would suffer.
My main point of contention though, is saying MS is a video game. To paraphrase you, this is not a video game. There is not a single element of gameplay involved, which is I would think required in a game.
This is a dedicated moviemaking software, just like iClone, just like some more expensive programs used by professional studios. It's no more a game then your internet browser. Actually less so. You can play games using your browser. You can't do the same using MS.
You're last bit, the base program was free only so long as it was in beta. Nearly every software company that releases open betas do so for free and then charge for the software once it's at a full build. Should they all keep it free too?
Just trying to give a little perspective

I do agree with what you have to say about the trial period. It should be longer.