I also think that just because you might be somewhat new to some of the concepts in BlitzMax, that doesn't mean you deserve to be cut down or used as a skapegoat for other people's aggression. If you believe you can do it and it's your dream, who is anyone to try stopping you.
I see this time and again. Telling someone the truth when they don't want to hear it isn't cutting someone down or using them as a skapegoat for anyone's aggression, it's good advice.
I actually think telling someone they should do whatever they want to do regardless if they have the experience for it or not is far more damaging in the long run. You may think you're being nice and encouraging, but if the person you're advising really isn't up to the job (YET) - and everything he's posted indicates as much - then all he's going to do is fail, get disheartened and throw it in the bin.
If he follows the advice given by H&K, GFK, and SSwift, he stands a good chance of getting the skills and experience he needs to make what he wants to make in the end. No one's suggesting he's stupid, or lacking in ability, because we all know that programming isn't particularly difficult. It's just a case of practice, starting slowly, developing your skills, increasing your confidence and you're there.
So yes, he can do it. But if he tries to do it now, without starting small and developing his skills, his chances are vastly smaller.