The way you framed it is a bit disingenuous. The reasoning behind the policy is that the government recognizes that China back then severely lacked any modern industrious knowledge. In order to quickly catch up, China decided to pour all its resources into a couple provinces that either had existing industrious base left over from foreign occupation or had strategic locations. As well as sending the best people over seas hoping to gain whatever knowledge necessary to kick start the economy. And it's not like the government simply forgot about the billions of farmers, one of the top priority for officials are poverty alleviation. It's a key kpi for any promotion within the government.

Now you could argue the implementation is not perfect, but given the situation back then I agree with this policy, and I'd be interested to hear how you would approach this differently.