The reasons why you have heard a lot of people including myself recommending beginners to stay away from fertilizer are that:
1) Most people would assume plant fertilizers work the same so they would grab what they use for houseplants or vegetables and use on the CPs, at same concentration -> bad endings...
2) Carnivorous plants are very sensitive to a certain minerals/ salt/ chemicals. You'd need a tested fertilizer at the right concentration for feeding them.
3) Most carnivorous plants are capable attracting bugs on their own. Some are rather good at it unless you have enclosed them in a container without access to bugs. Though they might grow slower without fertilizer, it is much lower risk than trying an unknown fertilizer on them.
4) Carnivorous plants in general live in nutrient poor soil mix, the excessive chemicals remaining in the soil will eventually reach a harmful concentration if we are not careful. Top watering and regular flush is highly recommended to get rid of any kind of build-ups.