Of course it is both legal and right. Don't make things open source then expect them to not be cloned. The benefits of open source are that it is not only makerbot that is contributing to the design it is the community. The downside? The community owns it.
It is legal and right to clone it, manufacture it and sell it.
However, I do see a moral issue in asking MakerBot community to donate a lot of money for this.
