They are not making it up, extreme gratuitous cruelty has been documented in commercial sheep shearing if you care.
https://www.youtube.com/watch?v=cCeKbMRlJUU
That video link was from:
https://www.woolfacts.com/wool-and-animal-welfare/shearing/
That article goes on to state that the same investigators uncovered cruelty at 117 separate operations, so does not appear to be an isolated incident by, "a few bad apples".
We had one similar in the UK a couple of years back, where a couple of "animal rights activists" got themselves hired at a farm to "document animal cruelty". Not finding any, they set about abusing some animals so they could film it.
I think they're still in prison just now, actually.
Here's some more evidence to support my claims:
https://www.theguardian.com/environment/2018/nov/16/secret-v...
https://www.scotsman.com/arts-and-culture/horrific-footage-e...
https://www.thestatesman.com/supplements/8thday/the-violent-...
Okay then.
As your link mentions, these sheep have been selectively bred to require shearing.
When it gets into warmer weather and it's time to shear them, their wool starts to thin, and you get a "rise" - a layer about 5-8mm deep where the individual hairs are about half of their normal thickness. In the wild, these hairs would break and the sheep would shed all its wool in great chunks, but it also makes it a lot easier to shear.
If you've tried cutting the "normal" fleece with hand shears you'll know how hard it is, and it will absolutely destroy mechanical clippers.
That's not to say that sheep haven't been selectively bred to have a good rise, as well as other desirable characteristics - it's not dog breeding, no-one is trying to select for a deformed snuffly nose to please a dog show judge - but the rise was there before they were domesticated, or they likely wouldn't have survived.
Scottish Blackface are about as close to wild as you can get, and they're famed for their wool.
Actually, I would. 24 hours isn't that long. Adrenaline is a helluva drug.
Brutal video, though. Ugh.
Given that this is PETA, I would not assume good faith here.
Finally, the original poster makes a universal claim about the nature of sheep farming, which your above anecdotes do nothing to support.