C2 has its limits, that's true. To me, it is mostly a great prototyping tool, a software that provides a solid workflow when developing small games. But clearly, it would be nice to be able to share and rely a bit more on third-party creations (solid templates, maintained plugins with support...). I'm looking forward to seeing the official marketplace grow actually, it may bring some of that.
I second you, Aphrodite, the way the whole C2 experience is built, but also the market it targets (people with little programming experience) influences the way third-party products may be perceived.
By the way, the Rayman team, Ubisoft Montpellier, uses an in-house tech from Ubisoft called the Ubi-Art framework. A few ubisoft studios are working on extremely polished 2d games, and they have pretty big teams, so it makes sense for them to use an in-house piece of tech.