I agree with the argument that these measures are very distorted. The GAAP measures will be more consistent as they are governed by standards. On the same note standards are standardised. They always struggle to cater for some industry specific measures. As a result certain industries will have better looking results simply because of the nature of their business.

Non-GAAP measures become useful if the users are able to calculate them for themselves as this removes the biases of the people responsible for the performance of the companies reporting on the performance. That being said, not all investors are CFAs. But I guess they can afford to get a specialist to analyse financial results for them.