I don't think this is really a very good allegory. The author has written 835 words and only managed to express that:

• blue food tastes kind of weird
• they're putting it in everything
• they're putting up the prices of blue food
• you can't get normal food even if you want it

It's not surprising to me that some people didn't get that it was about AI.

The allegory would work better if:

• production of blue food colouring took so much energy that they were bringing coal power plants back online and exacerbating climate change
• in order to design the blue food colouring, they had to steal every person's recipe books without permission and regardless of how private that information might be to the owner
• the blue food colouring could spontaneously make a food taste almost like someone's personal family recipe without their permission
• foods containing the blue food colouring completely lack any expected nutritional content, and when a blue food does contain nutrition it's just a random accident of the process
• scientific studies of people eating exclusively blue foods show that not only are they malnourished, but their body can no longer process normal foods as efficiently as before.

To make these points, I think the metaphor needs to be something a little bit more complex than "blue food colouring." Perhaps food made by a food replicator would make for a better example.