I often read and heard about burning tokens that were not sold when the ICO project was finished, I also knew that by burning the rest of the token was a strategy so the price of the token didn't fall, but if the DEV and the team didn't burn it was a crime? is there a requirement that the remaining unsold tokens must be burned?
It is just an act of generosity to keep your investors' faith always high. If you promise for doing so and then not keeping your words must be a kind of crime but not sure how many people will be able to find that devs are not keeping their words. Because burning is just a process of moving the tokens into some other address where they are not able to control the PrivateKey.
Basically, I like the concept of burning out tokens which are unsold as it will prevent the chances of unexpected sudden dumps. But for this to be happening in real life, devs must be honest enough. So, it is similar to just another part of their roadmap as we do see, many projects had come up with many plans but they were not at all following them later on.
I have seen many projects went for burning out their unsold tokens still they have got unexpected dumps. There could be many reasons for this and the prime one must be devs may not be honest as they sound.