Do academicians consider Challenges on Kaggle to be research-worthy?
One of the other uses I've noticed (besides publishing papers on a competition itself) is academics using a competition to demonstrate the application of a particular algorithm that they have developed and published.  See Steffen Rendle's libFM (Factorization Machines) winning the Grockit Challenge, and the winning team of academics in the Merck Molecular Activity Challenge with their use of deep learning.