I'll preface this by saying I love Hashinshin. It's just that I love him as an entertainer, not an educator or game balancer. If you don't know what happened that led to him playing Viktor here's the TL;DR:
Hashinshin plays Fiora vs. Viktor top. He loses really hard and says how mages need insane nerfs and to prove that, he first timed Viktor top in ranked (at least the first time in several years) and when he's trying to prove how broken he is, he ends up going 0/19 and being banned for intentionally feeding. Isn't that ironic.
And in classic Hashinshin fashion, he was complaining about how broken Riven is the whole time.
I think this is the best example of why a lot of what Hashinshin says is wrong. I know it's an anecdote, but you also have to listen to the other things he says. Some things I can think off the top of my head are
"All ability power from mage items and runes (and all other sources) should be reduced by 25%." Does he realize how ridiculous this would be?
He also said Kennen should get gutted to the ground with very little reasoning behind it.
Like I said, I like Hashinshin as an entertainer, not a balancer. Don't think I hate him lol