Pretty smart to leave bitcoins for your children because that will make them rich and they don't have to worry about taxes or anything. But maybe it will be for nothing because bitcoin may always go down and maybe another coin will become important.
Anyone that is responsible enough to think about the future of his children by investing in bitcoin is not going to make the mistake of not checking his investments, that will be a terrible mistake, however you are talking about a possibility that is very remote, right now there is no coin that is even close to surpass bitcoin and other developers had already ten years to try it so creating a better coin seems to be a lot harder than many people think.