Size doesn't matter

So they say size doesn't matter. This is true to an extent if you truly love someone then how tall, short, fat, thin they are shou...
well what did you think I was....
you people are filthy.
Anyway size doesn't matter so answer me this. WTF is a size "8" say?
Now when It comes to guy sizes it makes sense.  28 inches is 28 inches. Its a measurement that can be quantified and also gives you an idea of what size you are. With women its different size 10 means nothing. Its an arbitrary number. They could have called it "pinnini" and it would make the same amount of sense.
The really infuriating thing is that I could sort of see there point if these arbitrary numbers were the same across the bored. A 12 is a 12 in M&S, PRIMARK or TOPSHOP but its not. An M&S 12 is different from a TOPSHOP 12.
(Its not just  a 12 its a M&S 12, mmmmmm foood)
aaaanyway.
Point is that not only does the number mean nothing its no even a consistent imaginary number. What makes a size 10 different from a size 12?? Gain a little holiday weight? Well you gone up by 2.
Wait ...what???
Oh but only if you shop here. If you shop HERE then you've gone down 4.
Your just making shit up now right?
sadly no
This extends to male ware too to an extent. An XL shirt is different in every store you go into. On me an XL from PRIMAK fits like a dream ( if I were an African elephant) however if I try to squeeze my increasingly (L) frame into an XL from TOPMAN its like trying to put a double duvet into a single duvet cover.
Its horseshit.
Then of course there is size zero...
Who the FUCK thought introducing a size zero was a good idea. Surely size zero is dead??

"removes sunglasses"
"What have we got?"
"well serge it looks like she died when she bent down to pick up a pencil and she snapped in half"
"death by stationary how.... pointless"
"good one serge"

By adding a baseline of zero they have given lots of invulnerable teenage girls something to aim for. Before it was just "skinny as possible" now its "death"?
Now i am no fan of math, frankly one day I feel like math and I are going to have to have a gladiatorial fight to the death one day but frankly i think there has to be an alternative to this random bullcrap. If you are going to assign a random number at least make it consistent with other stores