Because it would be inefficient and people don't like it when you use their computing power for your own gain. I should mention that there are known instances of this happening. A site being compromised and a JavaScript mining applet has been added to the site.
Right... however ANY efficiency when already using a rig for an idle game is literally more efficient, hence why I wondered.
Also it wouldn't matter whether the mining benefits the owner or user. In reality if the user wants to try with the CPU, they'll be making $1 for every $20 wasted in power letting their computer idle hard. However that's still $19 rather than $20. You could at least give the creator the crypto rather than yourself if it's free which is kinda my point.
It's literally a case of I'd prefer nobody benefit rather than someone else.
You do know that PCs don't consume all the power when idle right?
I have a server with 2x800W power supplies and it idles at 110w. If I were to run a crypto miner on it my power bill will go up far more than the game creator will make.
The only winner in small scale crypto mining is the power company.
I assume you mean for the computer owner, not the game developer? Assuming it goes to the owner of the hardware, not really that useful. CPU mining is incredibly slow and GPU mining would not even necessarily break even on electricity costs. If someone wants to mine, they should just run a dedicated mining program. Wasting electricity to do pointless calculations for tokens is an outdated idea anyway.
If the idle game is running at 100% there is no power left to also crypto mine. If the idle game runs at 10% you could use 90% for mining but then you would pay for 100% energy usage instead of 10%. You'd probably end up paying more than you'd mine.