why not? It demonstrates the ability to hold a huge amount of information in your head at once, make rapid decisions in a high pressure environment, and do what are essentially Bayesian probability calculations in your head. I may be biased as someone that played poker to put myself through grad school and had a nice hourly rate by the end of it, but I think that it requires a high intelligence, the ability to emotionally disconnect from decisions, and the ability to retain and act on such large amounts of information that it's a definite positive. (It's also really boring and psychologically brutal at times and I wouldn't recommend it to many folks.)

I agree. I also played professionally for 3 years, and I found that when applying for devloper positions, my poker experience has been lauded as related.