Scammers trying to dupe people. Liars and trolls spreading FUD, trying to profit off gullible people or just trying to cause havoc for fun. People hating on each other because they have different opinions, insults flying low and pitchforks seemingly always at the ready.
All these people you mentioned are on my ignore list, you'll find that these morons look like they're the majority of the forum because they're busy trying to spam people like you off the boards because that's how they roll and it's a common theme on any forum the only difference is that on here there are that many people it looks like there's just a wall of hate, feel free to add the following people to your ignore list so you will have a much more pleasant time on the forums.
MoonShadow
markm
Inaba
kokjo
Raoul Duke
MysteryMiner
cbeast
cunicula
evolve
iCEBREAKER
dank
Matthew N. Wright
misterbigg
Maria
capn noe
Hawker
usagi
blablahblah
Gurrty
RandyFolds
danieldaniel
Viceroy
ElectricMucus
FirstAscent
ursa
AndrewBUD
Augusto Croppo
MPOE-PR
Agent Provocateur
mem
fgervais
gweedo
Xian01
solareclipse64236
Darktongue
Gemdealer
underminer
subSTRATA
SEC agent
farlack
johnniewalker
lunarboy
flavius
nexusakachus
qbits
surebet
sublime5447
Actor_Tom_Truong
Milkshake
bernard75
nwbitcoin
dimaniac
mai77
wopwop
AnonyMint
MatTheCat
oser41eric
antibanker
rhinospray
puffpuffpass
101111
cypher-punk
Jaroslaw
FinShaggy
BTCIndia
just_me
alyssa85
zerodrama
Coinseeker
Fixx
BitCoinNewGuy
crumbcake
john_nalpa
JohnRambo
NWO
chowderman
r3wt
kodo
sardokan
lovedbits
crumbs
monbux
ironcross3602
dave0003
sampathneo
Nigeria Prince
AnhBen
JJBTCSeller
gentlemand
Ibian
Dafar
hilariousandco
eternaluniverse
jballs
Honeypot
guybrushthreepwood
thaaanos
Here_To_Help
Armis
syabiz
thelema93
drchelsea
When it comes to community sites, I refuse to join any that don't have a working block/ignore function simply because it's completely taken advantage of, much like how marketers and scammers take advantage of the fact that your home phone line doesn't have a block/ignore function as well.
Included in the list are the following types, some of which you've mentioned: FUD Spreaders, racists/xenophobes, people who use personal attacks when they can't get you riled up any other way, scammers, spammers and all round in general fairly unpleasant people, funnily enough I think precisely because of the ignore function a lot of these people have given up posting now because their trolling doesn't really work.