I had some lovely allium flowers this year from bulbs I planted in large pots. What would be the best thing to do with them now?
I'd let them die right back, remove the faded flowers and replant them in the garden if you have a space.
No reason. At all. They are the same family. It's just that we treat and see them as different things, many vegetables have pretty flowers. We had loads of pea seeds which we planted and then picked the flowers, just as pretty as sweet peas and a much better crop of flowers than we have ever had peas!