If there isn't an instance of nutrient deficiency, pest damage, or over/under watering my first guess is persistent herbicide damage. Did you happen to use any mulch? Straw? Hay? Compost? Manure? These are all vectors of persistent herbicides like Milestone / Grazon.
Pineapples aren't good at absorbing nutrients from the soil and are usually foliar fertilized. You didn't mention how they were getting fed but that is something to consider.
Pineapples aren't good at absorbing nutrients from the soil and are usually foliar fertilized. You didn't mention how they were getting fed but that is something to consider.