I live in the PNW near Seattle, but because it is summertime, nighttime temperatures are consistently above 10 degrees celsius and daytime temperatures are around 27.
It started looking like this several months ago when it prepared to flower and it was still indoors for the winter. I put it outside and the condition kept deteriorating. The fruit also seems to not be getting any bigger.
About nine months ago when I planted it I filled the pot with potting soil and about two months ago my mum covered it with sand to keep water in or something. She raises a lot of houseplants so I assumed she was experienced on this matter.
I water it about every three days with about 250 ml water and a few drops of MiracleGro (it also occasionally rains). I read that to help iron deficiencies people put rusty nails into the soil so I stuck some old screws into the soil.
Is it the sand? I have a sneaking suspicion it is the sand.
I hear homegrown pineapples don't get as big as store bought pineapples usually but I don't know how big they get.
Most pineapples don't grow as large as the ones you see in North American supermarkets. OP's pineapple is probably ready to eat now.