the way the topic has been reduced to hmmm, i do not wish to elaborate at all on why Devaki had to have her sons to be killed by Kamsa.
but a point worth mentioning here is, do not critique it because you watched all 50+ episodes of Mahabharat. read it. those of you who are commenting on it for having watched it on tv or the internet in the form of a movie will have known only a fraction of what is a huge fountain of knowledge that when analyzed through a clear mind will make lot of sense, no matter how mundane and weirdo it reads and sounds!