I emailed Lego asking them why we could not give proudct ideas, and why BTTF would not be a good choice for Lego. They didn't really answer the second question but oh well. Here was their reply to my email
Dear Mr. Burninator,
Thank you for contacting us on 07/04/11 and for your interest in LEGO® brand products.
As you know, versatility is the foundation of LEGO toys, and, since LEGO enthusiasts and their families are so creative, we receive many new product ideas from parents and children. We sincerely appreciate your generous intent-it is quite a compliment when a consumer voluntarily takes their valuable time to share their thoughts with us.
Each year, hundreds of new LEGO sets are introduced and our assortment now includes exciting new items such as games and puzzles. Within the LEGO Group, there are several research and development areas, whose sole purpose is to formulate new product ideas, compatible elements, instructions booklets, etc. From start to finish, a new item will require in-depth research and design work long before it appears at your local store.
To avoid confusion about the origin of products during that development process, we have a company policy that prohibits reviewing third-party ideas and suggestions, or even discussing any ideas for new products that enthusiasts would like to make and sell under the LEGO logo through a licensing agreement. Although this position may be difficult to understand, it has been carefully considered by the LEGO Group. The policy is in place because we have invested considerable resources in our own product development departments, which utilize the efforts of professional designers as well as other creative personnel. Those professionals work hard to independently develop our existing product lines and develop ideas for new products within our particular business areas.
Thank you again for contacting us. We wish your family many happy hours of creative building with LEGO brand toys in the years to come.
LEGO Direct Consumer Services
There you have it. And if you think I spent a bunch of my time writing that confusing reply, I didn't. It was an actual reply. Go ahead and email them if you don't believe me.