Haha, as much as I indeed understand the angle you both are coming from, I still will not support that gambling should be seen as an investment, why, because gambling is not an investment in the first place.
Seeing and talking gambling as an investment has its pros quite alright, but if you check it, the cons are much more than the pros.
Taking gambling as an investment could also be liken to taking gambling as a business the gambler is possibly expecting to profit consistently from, this could lead to alot of gambling problems like over gambling and addiction, over gambling means that, the gambler starts spending much time than necessary in gambling, which in turn can lead to addiction.
So, for me, I think it's better or best for us to always see, and take gambling for what it truly is, trying to see and take it as something it's not could be disastrous.
Yes in the general opinion, gambling shouldn't be taken or seen as an investment, but also if we can apply some investment mechanisms in gambling and also be able to effectively guide ourselves and our finances using such techniques this could be of a great help to us and sometimes all that we need is just an approach to follow and nothing more.
If you recall that in my last sentence on that comment, you will read where I mentioned to always avoiding the practical perspective of taking gambling as an investment.