Of course you can't compare gambling and investment because both have no similarities and should not be seen as the same because they are two different things, gambling risk is so much that you can't get any thing out of it once you gamble and lose your money. If you don't want to face the risk of losing money it's either you avoid gambling or you gamble with a budgeted amount.
People who spend their money on gambling may be doing so because of how they intend to make fast profit since they would have to wait for their investments to mature because they can take profit.
Gambling and investment both have individual financial goals, risk tolerance levels but totally on a different scale and it only takes those who can really distinguish those fundamental differences between the both concepts to really understand the they totally different. I look at people who classify them in the same category as people who are naive and ignorant because it'll be lame to even use the same approach on both because you'll end up making several financial errors.