[strken]

The problem for the developer considering a CLA is that if you take any contributions at all, you now have a community of people who A) understand your source code and B) have had their contributions rolled into your proprietary product, possibly against their expectations and possibly leaving them rather upset.

With 0.1% of commits it's not a likely problem, but if developers are making significant contributions then there's a good chance they'll fork your product as of the last LGPL commit and keep developing it as a direct competitor. It's safer to just not take contributions at all.