Bloom is good for Halo in my opinion. I mean in most shooters you have to aim down sights for acceptable accuracy which comes with slowed down combat, Halo doesn't allow players to ADSS for most weapons, and hip fire accuracy is fantastic by comparision to most other games, so obviously there must be a system that slows kill times and oombat. That's where bloom comes in, it results in paced battles.
So called "Skilled" players argue bloom is bad. It isn't, without bloom everyone spams all the time, just try ZB slayer, so if someone argues spamming is bad and noobish but claims bloom is bad, they are a hypocrite. The amount of bloom Halo should have is debatable, but I have no doubt Reach is better thanks to the addition of bloom. Yes it adds a luck element of sorts, but shooters are very much luck based, its just hidden luck. The skill of the players you're matched with, which side of the map you spawn on, hell with the new voting system, the gametype can be very much different (like the difference between AR and DMR starts). So yeah luck plays a factor, but a good player is a good player, is a good player, and minor out of the ordinary events should in no way detract from their preformance in any noticable amount.