Original Fiora was fine in terms of counterplay and counter build.
Lets start:
Original Fiora was doing AD damage.
Which already opens 2 counter build options: Build HP or Build Armor.
Building either Armor or HP was increasing the amount of time Fiora had to fight to kill you.
Her Q was a long range dash, which opens up for counterplay options: displacements.
A Janna Q, a Thresh flay, a Gragas ultimate, etc. Everything would've stopped her engage.
She was building glass cannon.
Which means, you could've easily blown her up from the face of the earth.
Her ultimate had 400 range.
Which means she could have gotten hit by any CC with over 400-500 range. Which include:
E,
QR,
Q,
passive QR,
R,
QR,
QR,
QRE,
Q,
QR,
Q,
E,
E,
QE,
R,
R,
R,
QR, ok I got bored trying to list all abilities, but you get the idea.
Her ultimate damage could've been avoided on primary target with shields and heals. Meaning counterplay in form of:
heal (with +armor and mr, it would've only been viable in s6 with the new masteries, in past seasons ali didn't do much other than intercepting her ult and ult himself),
W,
W,
W,
whatever skill is his shield,
RE,
RW,
R,
RE,
W,
heal,
heal,
heal,
heal
Next, her ultimate could have been counter builded with
viable for AP champions.
Next, her ultimate could have been avoided by champions such as:
Also counterplayed by
and
(released after fiora rework).
Hmm, there's more.
Fiora's entire kit was about auto attack so,
reduced her damage by 10%.
And finally, her steroid was an auto attack speed burst. Which was easily stopped by Attack Speed slows such as:
,

Futhermore, she had to run though the enemy team to reach her targets. So, AoE zone control was highly effective, such as:

I'm sure I've forgot a few more ways to counterplay/counter build the Original Fiora.
But the point in case is, the community made it seem "toxic", not that the champion was as such. There were plenty of ways to play against the original Fiora. Now, since you guys bitched so much about it, have fun dealing with % max hp true damage and can block any cc, go counter play that.