or the source code but these guys don't reveal their code as maybe somebody will further develop their mods/bots and they will become annonymous, or not ?
I don't think that is a very fair statement. People create modifications for different reasons. Anyone who releases software free to the public has already done the world a big favor with a gift of their time. Whether or not they choose to make the source code available with it is their decision. Some people may be novice programmers and don't want to deal with the stress that comes along with pros nit-picking apart their code -- that can be extremely aggrevating. Even if your original goal was to learn how to program better, some people are just asses about the way they "constructively criticize" other people's work.
Other people may use what they consider to be private algorithms and optimizations that they hope to use some day in a for-profit project. They have every right to keep these types of things private.
Still other people release software specifically for the feeling of pride they get by providing something useful to the public. To some this may sound greedy but not to me. They have already donated their time to create the software in the first place. Making it open source would potentially rob them of the only benefit they are deriving from their work (personal satisfaction and pride.)
I think it is unfair to criticize any freeware developer for not releasing their source code. It is FANTASTIC when you find people willing to share with the public in such a magnanimous way but I think we, as a community, should not expect it and be thankful for the occasions when it occurs.
But hey, thats just my two cents, you are welcome to disagree