What I don't understand is what financial trading has to do with casino roulette tables. I don't think of myself as a gambler and don't know anything about it. But it looks to me like there are a lot of red and black blocks on a wheel and you place money on the chance of a little plastic thingy (is it a dice or a ball?) landing in one of those blocks - how many are there? What are the odds?
On the other hand, a stock price goes up, down or sideways. So only really two options there. Yes, you can gamble blindly on a 50/50 win, or you can reason on a calculated risk. Speculative trading should be a calculated risk (like most things in business, especially a start up) and not a blind gamble. But no business should be a 50/50 gamble. Hell, who goes into business on those odds? Who does ANYTHING on those odds. Not even a bungy jumper will entertain odds like that. There's a risk in everything in life - even driving your car to the supermarket carries some risk but it's minimal which is why you still do it. But if it was 50/50 would you take such a risk with your life just to buy a pint of milk? Of course, blindfolding a 10 year old who has no idea how to drive and throwing him the keys is probably not going to end well. It doesn't take a rocket scientist to figure that out.
I agree that most gamblers will lose - at games or in business. Calculated risk has different odds and it's all about improving your odds for success is it not? I don't think gambling offers you that possibility and I don't see the similarity.
EDIT: unless you can sit at that roulette table with a pot of black ink and start colouring in the squares!