If we're going to implement a tax on the stupid, I'd personally prefer if it were billed in crowns, so it pushes the exchange rate in my favor rather than otherwise.

All forms of gambling (including lotteries) are sometimes called a "tax on the stupid" because playing them is really obviously a bad idea (financially speaking) in almost all cases. You lose money on average, even before taking into account that the occasional win is worth less than it looks like, due to diminishing returns, taxes, and various other reasons. The only people who make money on gambling are the organizations taking a cut for running the game.

So if there's a weekly lottery, the big-picture effect of that is simply to take money away from the players who participate (a lucky few make a profit, but almost everyone loses, and the player base as a whole becomes poorer). If the lottery destroys energy, then people will be bidding the same amount of crowns to get a smaller supply of energy, and the cost of crystal energy will go up. I'm a net consumer of crystal energy, so that's bad for me. If the lottery destroys crowns, the opposite happens, lowering the cost of crystal energy, which is good for me.

Unless you're suggesting that the lottery be made so that it pays out more than people spend on it, in which case you're just suggesting we give money randomly to already-rich people, which is a horrible idea.

Actually, one potentially interesting thing you could do would be to have a lottery that costs crowns but pays out a fixed amount of crystal energy every day regardless of how many people enter; for example, sell tickets for 10 crowns, select one random ticket out of all the ones bought that day, and give the buyer 100 ce. Now, instead of just being a lottery, it's a way to convert crowns into crystal energy. But the exchange rate self-adjusts, because the more valuable the energy is, the more tickets will be bought, so the more crowns will be used up trying to get it. (Note: number of tickets sold would have to be public for self-adjustment to work.)

But that's basically just a complicated and largely luck-based way to trickle crystal energy into the game without anyone paying real money. Which would benefit me, and could arguably even be in the interests of the publishers, but it seems to cut against the design philosophy they've demonstrated so far, so I'm not holding my breath.

Don't they already do that with lockboxes and bribes?

I agree with what Oakgear said.