People I have worked with will know that I am always banging on about the merits of the open cup. I often meet parents of toddlers with eating problems who still drink from a bottle with a teat. This is really common - it's extremely easy to get stuck with a habit that is comforting to your child, especially if it's part of your bedtime routine. Making transitions like this ( for example, ditching dummies / pacifiers) takes time and energy that are in short supply for most parents.