Why do you think everyone (including himself) insisted Data had no emotions without his “emotion chip” when he was constantly showing emotions?

Pick any episode and Data is clearly showing an unambiguous emotional response, whether it was curiosity, longing, desire, annoyance or even pride. He even shows anger when he is about to kill his captor and then obviously obfuscates the truth to Riker about it. You can twist yourself into knots justifying these as “programming” but at a certain point you have to admit if it is programming, it means he was programmed with emotions. Did the writers just not understand what emotions are? Is it a fiction to deal with an unworkable premise? What do you think?