Do you follow cooking instructions on food packets?

I have some frozen broceli and lots of other vegetables in the freezer. It's all boil in a saucepan only according to the instructions though. I very was hungry so thought to hell with the cooking guidance, instead put the broceli and sweetcorn on the baking tray with extra virgin olive oil, sea salt as well as black pepper. And it was the most delicious meal I've had all week.

Why do we follow these silly rules like they are set in stone or something?!