exotic fruits: As a right-handed parent I take offence. I think my DD is pretty happy that I intervened at school, and school didn't seem to think I was making an unnecessary fuss (in fact they expanded their policy for teaching left handers so teachers had guidance... & if they don't have guidance, which is what the policy is, how are right handed teachers to know...? Now that's what I call common sense).
Why do you agree its necessary for sport but not for writing? Adaptations to method are sometimes needed for both. And it's not 'new' for sport; my middle aged brother was national standard at 3 events, 2 he did left handed and one right handed, because teachers took the trouble to work out with him which hand he was best at for different events; he's not alone, sports history has plenty who were right handed batsmen/left handed bowlers (or vv).
If left handed kids were started off by looking at how they might find it easier to hold a pen, analogous to how they are shown how to use equipment differently in sport, they would develop writing techniques that meant they didn't smudge before they get to the pen stage when, like the OP, some kind of remedial action is needed (remedial means getting it right after the event, and doesn't mean that they are less able, before anyone else moans that I'm claiming it's a disability). Another analogy is playing a musical instrument: it's best if you're taught good technique from the start and kids don't necessarily pick up a pen or hold a... flute, or whatever... in the best way for them.
With regard to your earlier comment "younger ones are calling it a special need and wanting policies on it", I suspect I'm older than you are, and even if not please don't assume I'm some wimpy juvenile mum who screeches as soon as things don't go her way. I just don't see any point in not sorting things and our school took on board accommodating the needs of left handers (and yes, sitting on the left hand side of a desk is a 'need' - but I'll drop the word 'special' since you object; it just came into that part of their school policy and fortunately parents there didn't get strung up about what it was called, just happy to see it dealt with).
What I do know from my aged viewpoint, OP, is that the effort to get left handed DD's writing sorted was worth it. Approaching Finals now, she, my second youngest, is almost at the end of the long road of exams, but along the way fast and legible handwriting has been so very helpful.