The m99 is wrapped in the story of how a very vocal and very forum active minority removed content from the hands of nearly all killing floor players. Only games of friends are going to fund a sharpshooter the extreme quantity of cash needed to fill up on ammo. Anyone else just queueing a public game wont touch the weapon. The existence of broken, useless, or repetitive content in any game is a flaw that saps value from the experience.
Let's consider the perspective that the number of players registered for the forums are a minority and the anti-m99 crusade was a minority of a minority. If we could actually get a weigh-in of all killing floor players, many would answer the concern of m99 over-poweredness with "shrug" and the notion that bullets should cost 250$ a shot with, "That's ****ing dumb."
Without re-hashing the back and forth of "the gun is too strong." and the antithetical "changes the nature of the game and I'm ok with this" I would like to point out that it's a common expectation of the sharpshooter to have the play style of sitting behind your mates and taking care of large threats with head shots and this play style doesn't really exist on high difficulties and doesn't really matter at lower difficulties due to the bonuses of perk progression.
The crossbow isn't really viable for fleshpounds due to the specific "crossbow headshot damage resistance." The crossbow would pretty much be comparable to the m99, if not for that statistic. What's left over is the ever ubiquitous lever action m14 pairing. If you enjoy that as the end all of sharpshooter play, kudos. I still find the m14 laser sight to be a source of headache as it's often hard to see and the iron sights are the worst in the game. Furthermore the gimmicky methods of utilizing those weapons for fleshpounds doesn't lend themselves to casual and chaotic gameplay.
There are some players which can put an m14 clip into a fleshpound's face in a variety of hectic circumstances but, honestly, I haven't met any of them. For the most part, I endlessly hear the complaints of "who raged the fleshpound" "keep the trash off me" etc... As if sharpshooters are owed the ability to take a calm, strolling, fleshpound that's facing them in a serene vaccuum.
/queue prolonged sigh
It's a zombie massacre apocalypse... thing. To keep it fun and exciting players should die with some regularity and maintaining the threat of the fleshpound is probably a big part of that. I just wish some more consideration to the overall vision would be offered in the inclusion of content. I was really rooting for the inclusion of the Braindead hunting rifle as opposed to the m99... maybe that was just me. If there was supposed to be a single-player damage ceiling to taking care of fleshpounds in suicidal and HoE perhaps some alternative effects to damage should have been considered. The m99 being the one weapon that could snare an FP with a shot to the knee or something, who knows. Game designers and modders are creative people, I imagine, and probably wear lab coats. As it stands the sharpshooter now has two scoped weapons that are essentially a disappointment.
I was not a fan of the m99 inclusion but I have to recognize that it certainly added a top weapon to the hierarchy of sharp shooter as opposed to the m14 with terrible sights and the crossbow with specific "headshot resistance." I imagine the criticism of the gun would have been significantly less had it been included from the game's release. But now the use is unfeasible due to the follow-up solution of "make it too expensive to use." It's just sloppy on both counts. Both the implementations and the knee-jerk forum reactions that have ultimately failed to make the game any more fun over a series of patches and merely prolong the status quo.