Basically what Zeouter said, it pales compared to Halo 4's other enormities. Yeah, the devs were right, you don't really notice it, which begs the question why include it at all?
Plus it falls under the UI complaints which have been practically universal. Speaking for myself, I think it's underestimated how damaging the new kill feed, medal and white text UI is to that feeling of awesomeness that used to accompany multi-kills. 343 spoke of how intrinsic weapon audio was to the weapons feeling of power, impact and weight. If every time you shot the sniper it sounded like a guilty fart in a hospital waiting room it would negatively affect the feeling of that weapon, right?
By the same token, when I snipe an opponent in the head in Halo 4 and it tells me I got a generic 'sniper kill' in gross capital white lettering above the reticle it's a bland, dilute unremarkable feeling whereas the visual distinction and impact of seeing a sniper headshot that stays on the screen long enough to register in the previous games was just as important to that crucial player feedback loop as shield flickering and meaty weapon audio.
I'd still find sniper shots to be as awesome as before. Having textual confirmation of a goal in FIFA doesn't downplay how awesome the goal was. Why on earth would it?
That's one extreme I guess you could say. I have found it quite useful. I throw a plasma and run away. I get the kill. Did I stick or were they just in the blast radius? Boom, I can tell right away. '+5 Assist' is probably the most useful addition to my game too.
You say it was crucial feedback but you always had the generic sniper kill text on the left or the headshot medal. Are those not, by your definition, also limiting the awesome feeling of seeing the shield flickering and hearing the meaty weapon audio? Why so is one, literally tiny, piece of info suddenly the straw that breas the camel's back? Why is it that medals and kill feed text are a-ok but offsetting some of that to a more detailed, central role, waaaay more damaging an experience than ever before?
If the snipe you just got was awesome, why would some text you admittedly don't notice ruin that moment? I notice the text probably because I am a shitty enough player to use it more than a better player would. I get railgun kills and the combination of the hit markers plus the text (essentially 'kill confirmed') is enough of an awesome payoff on it's own. Stick around to watch the connection? Better still. I just don't see how, on any level, text can limit that payoff.
I take far more issue with the kill feed being less intrinsic at a glance. It's a bit too generic now. I find it harder to tell which team just got a kill. The white text is such a non-issue to me. I mean, I've been vocal about my gripes with how the UI tells you what you've unlocked pretty recently. Saving files can only be done with 'y' for some reason? The whole saved film area of the menu is a drak place of confusing tabs to me.
White text cripples the feedback system? I disagree.