Let's assume you're right, and that many poor people have no opportunity to better their situation. That doesn't change the fact that some people absolutely do have the opportunity to better their situation, but choose not to because their desire for a better future is satisfied by the fantasy of winning the lottery. The lottery acts as a drain in these cases, not only on the individuals who continue to stagnate, but to the rest of us who would benefit from those individuals contributions.

I'll also note that I fundamentally disagree with your statement. Everyone has an opportunity to create their own success. Obviously not everyone has the same kinds of opportunities or the same number of opportunities. Those of us with enough time to comment on Hacker News probably have dozens of opportunities PER DAY to create our own success, whereas a poor black kid from Baltimore may only have one, and it may require him to wake up at 4am to go to work or stay up till midnight to educate himself. But those opportunities still exist, even if you're poor.