Spinning is only so common and considered so powerful because not many people punish their opponent for spinning on them and when they see spins lots of people panic and and just go full defensive not even using counterattacks when they do get parries because they're too focused on trying to block the next spin swing.
It's not even practically effective against high skill players who can read the spin attack animations well - they will still parry your 720 degree quadra feint spin attack then land 2 full damage hits on you while you're trying to do another spin.
I dunno, check that vid by cerq where he fought that dude for a stack of steel or 1000g or something. The guy was spinning hard each time and cerq parried every one, but the part that was missing was the 2 full dmg hits. He still won handily, and it was never close, but it was still a whittle fest. But yea, I'm literally taking a step back when people start to spin. Usually people have to run forward to hit me. The only time someone got a true like... derpy stationary macro speed spin to where you can't read it well on me was some miscreant around fab when I was on a new char and encumbered w zombie heads, and best part was I guessed the parries. Still died cuz I was taking dmg thru parries :*( but the reason IMO it became obvious that it was a macro was because he got parried a lot first then started busting out that shit which was V fast and V unlike his play style.
Otoh since I haven't been able to wrap my brain around incorporating parry into my 'movement play style,' I get massive battered if people get in on me w/ o even feints. Same w/ excessive feints tho (most of the time can just dodge or move so I get 0 dmg) ... some people can do it, I'm sure, there is def a skill cap that has not been reached in terms of actual feint skill/movement. At least not that I've seen. I still remember when Tek time stamped a vid of me trollin w/ a katana after the swing speed change, and he was like "didn't even react to the swing," it's like yea cuz I didn't think he was gonna hit me (and he didn't, but sometimes I do get hit, dunno if it's desync or what, so putting up a block is SMART but it's a surprise when people do tag me.)
And I'm w/ other dudes, said it before... might sound like an excuse, but I'm not practicing this shit cuz I know it's gonna change. I actually thought it would be changed way earlier. I somewhat have changed to adapt to facing it, but I still get dunked almost every time straight on. The only time I'd scrape a win is if I had similar armor/dmg bonus to the person... but that's v rare, too.