I don't know why people say bitcoin is gambling. Its not gambling. You are investing your money and time. You use your internet. So its not gambling dealing with it.
Those people who said it is still not know what bitcoin really is. They judge bitcoin of what they hear but they still not experience using it. Bitcoin is really not a gambling because it is a type of job where you can earn. The difference of it in the other job is your salary is a virtual currency not a real one but you can still use it.