Projectile Spam: Defined.
This whole skill = hit-scan association is really retarded. It takes a bit of skill to use hit-scan, or do anything in this game, don't get me wrong, but I think people have this seriously false conclusion about how projectile fire "can be used".
Everyone has a different definition of spam is seems, but one of the common ones seems to be firing at someone you can't see, achieved by exploiting the time it takes a projectile to reach it's target. This concept in itself is mostly balanced, and one on the recieving end of said fire can prevent it from happening to him or her, and that is a greater skill then use of any hit-scan weapon IMNSHO.
Ears are your friends. Pickups, and moving predictably are not. These are the first two lessons in preventing from being "spammed by projectile fire". If you can see it comeing, if you can see your attackers weapons' barrel, then him hitting you with said projectile fire takes far more skill then him using a hit-scan weapon at that time.
If you fire at somone you can't see, then that is either an educated guess: balanced by your ability to anicipate your opponent, dicatating whether you do damage, or waste ammo, supressive fire: forcing your opponent to take a different direction, or take damage, or use of senses other then your eyes: firing at known locations of sound cues.
You can class any non-sight driven projectile fire into one of those categories, and at any given time, I consider none of them luck on either side, good or bad. A mistake is made by someone each time, and that mistake is paid for in some way by that person. If you think it has anything to do with skill vs luck, or lack there of, there is simply something about that situation you are not considering, and you prolly have something to learn from it.
In case your curious, my personal definition of spam, is one spraying a weapon, constantly, without intent of letting up on the fire of said weapon, usually less then aimed, sometimes "pointed", and doing so regardless of change of situation, or action of target. For the most part I would consider spam in this game non-existant in most of the gametypes, and situations I play in. Minigun use being a rare exception.