Certificate transparency logs are essentially a blockchain. Would you prefer Google and the other stakeholders to run an SQL database instead, containing these logs?
To be honest I don't know anything about certificate transparency logs. Maybe they should be on a blockchain. It doesn't mean money should be on a blockchain.
I mean this is just a dumb argument. Who hosts the database? How do you trust them? It's as if people are being wilfully ignorant when they use this as a line of attack. Go learn about Byzantine fault tolerance and think a bit about what problems it attempts to solve