When it came to using the Hammer, it would require a fair bit of skill besides just “hit left click and win” and, more often then not, I’d find using the hammer to be a well worse off option for fighting against something that just using normal weaponry. The main reason that the Hammer was considered “Overpowered” was not due to its statistics, but because of those who wielded it being capable of properly using the weapon. Even then, I’d find it hard to use the Hammer in even the best of situations like funneling down a tight corridor and fighting one to one. And with the new addition of Shades Task Force with the constant GS3 spam, the new CI CCs making a huge come back, and for $10 buying someone into a 250/250 PKM three slot Heavy class. The Hammer put some balance into countering the massive German styled Blitz Krieg that would wipe all who didnt happen to be high command in Nu7 or decently ranked in E11 or A1.
Furthermore, while MTF might have a rather large amount of MTF CCs, a good amount of them cant even come close to compare to the CI Recon Force or the “Seeker” CC, with there being a fair amount of dead CCs -such as Omnicron, E11 Last Stand, Iota-10, Site Protector, Site Inspector, ect and ect- and with even fewer being able to bring in the equipment necessary to withstand the absolute raw DPS of Negevs, PKMs, GS3 spam, Shawed Off Spam, and even Awp and Flare Guns to an extent. The only ones that come to mind that have a decent chance at putting up any actual resistance is Rho-36 Occult Operative, Magma Defender to an extent, and Osprey-1 to an extent.
Lastly, to expand a bit on the “Hammer not being as OP as you think,” I’d like to add that many times I have lost fights against people while using the Hammer due to the simple fact that they knew how best to counter the weapon or because it just simply was not anywhere good enough. I’ve had times when Gensec would wipe the floor with me, OFCs included, despite me going in a rush with my Hammer and other D class for support, including Reznovs and other D Class CCs. I have been destroyed plenty of times by skilled PVP players during CI raids with my Hammer doing little besides maybe a hit or two that simply couldnt output enough damage fast enough to kill off someone. I’ve even had a few times where I couldnt kill someone simply because they were able to outrun my 90% Mobility Speed. The Hammer isn’t an instant God Weapon that would smite those who happened to be close, but is just simply another situational weapon with its own Strengths - like high damage and good hit reg - and its own various downsides - 90% mobility, slow swing speed, useless at even medium ranges, situational, and sometimes just outright DPSed.
TL;DR: The Hammer isnt as bad as people say, its just the people who used it were good enough to use it correctly.
Edit: gonna add more to this
In addition to what I posted above, I would like to add that, in its current state, the Bat can out Damage it and the Scythe can do the same damage almost twice as fast. Keep in mind that this was a 20/30$ dollar weapon that was exclusive to just the 2019 Christmas Holidays while the Bat is a permanently and non-time exclusive weapon. Furthermore, due to its state as of now, there is very little reason to use it even over something like the Hatchet or the Bat due to you becoming more of a target from those you attack when using the Hammer. This all accumulates to it being almost useless in comparison to the Scythe, Bat, and even the Hatchet with two out of the three being on the store permanently and even having sales on occasion.