Not the parent poster, but the way I look at it is this:
Making money off speculation is a net negative for society as a whole. Very little has changed about Bitcoin except that people will pay more to buy some of it now than they would 5 years ago. There's not any fundamental reason for this; Bitcoin itself isn't even loosely related with any kind of commodity or anything "real" that could drive its growth. It's just people hoping that there will be a "greater fool" in the future that will pay more of it, and that there will continue to be greater fools for as long as they decide to stay in the game. More charitably put: it's people who really believe Bitcoin will change the world[0] of finance someday, and want to make sure they have a stake.
I'm not entirely opposed to making money via those means, but if I were to do so, it would be at someone else's expense. At least if I invest in, say, an index fund, that money goes toward actual economic activity: building things, selling things, etc. (no, that money doesn't go directly toward that, but after several convolutions, that's what it's supporting).
When I think of cryptocurrency specifically, I also think of several countries' worth of electricity being burned in support of the various currency networks, and I get a very sour taste in my mouth.
So I think it's hard to say that I'm for or against making money from speculative activity; it depends on the particular speculative play and how much I can stomach whatever external harm or negatives that speculation causes[1].
[0] I do believe blockchain tech (in general; not Bitcoin specifically) does have a lot of potential, but I don't think any of the current cryptocurrencies are going to be around for the long term. If the blockchain does change the world in some way, it'll be a new application of it that we probably haven't seen yet.
[1] I just want to be clear that I'm not trying to take a holier-than-thou attitude here... I'm likely comfortable with some negative externalities, just not all, I guess.