what i don't understand is why then he won't sue them instead of wasting time nagging in a forum.
Who is he going to sue exactly? there are a dozen of folks who do that, most with no known real identity, the resources needed to secure such an open-source code are far more than what Kano or anyone else can afford.
In fact, even the devs who have more skin in the game like Jeff Garzik who wrote the cpuminer code or CK who then forked cpuminer to Cgminer, and despite that fact that he is the major dev in this and if I am not mistaken Cgminer functioned for a while before Kano touched the project, the latter seems to be the ONLY person who cares about this.
Even the other devs likes luke-jr don't seem to care, almost all of the major devs who contributed to the project one way or the other are now successful millionaires who probably don't even know about the existence of these custom firmware in the first place.
While Kano isn't doing anything wrong by "chasing" those who violate the license of the a code he heavily participated in, it's just sad that he does not have anything better to offer for the community other than nagging about people breaking the license which is no matter how you look it at is just a waste of time judging by the fact that the custom firmware market is only growing, but well, it is what it is.
I did take it to theymos, but he ignored it.
Because the forum is not a court of law, it does not even moderate scam, you can literally create a topic saying you are a scammer and you are planning to scam someone and the mods will most likely not delete it (unless it breaks one of the rules which scam isn't one of them) let alone topics that violate a certain license, the forum will not project the license on your behalf, also, nagging about it here will change NOTHING, if you want to stop all these folks from making money off your code, stop nagging and start coding, add the auto-tune part and let the users use your free version, at that point, nobody will be using those custom firmware that take 2-4% fees.
If you take the above seriously and do decide to start coding the cgminer again, I am sure the miners' community will fund the development, I will be the first person to donate and will help you spread the word to get enough donations to keep you going.