All very good points!
I have some others to add.
1) trap brake dust which could interfere with proper brake application though it would take awhile to build up.
2) trap moisture and the brakes might not dry out after a good puddle dowsing quickly enough or freeze up in cold weather
3) add unsprung weight, not much but all unsprung weight is a negative aspect to consider
4) the money could be used for more worthy mods
Already mentioned so just expounding upon, they are like fake hood scoops and turbo badges, Buick style fake front fender vents, etc....
The other day I saw a nearly brand new very nice Audi with a very tacky fake hood scoop and no other mods, what the hell, how could somebody smart enough to make the money to drive that vehicle and ignorant enough to do that to it is beyond me