i wonder why people still want to write on this topic .The dev now only thinks about $ and not releasing his private miner.Why do you even still thank him and want to donate btc?Just donate to new devs who releases xmr and new coin algorithms
Out of respect and gratitude. The devs are under no obligation to open source their work but they usually do. I feel like I owe a lot for the devs here (especially Christian) as their work earned me quite a bit of money. I haven't donated much yet (come on GTX 800 series

), but I won't forget to do so.