Being controlled by someone or some company will make people think twice before entering or investing. So if bitcoin is centralised, then the price now should be 100x or 1000x lower than now.
Or no price at all. If it continued to become a thing, even though it is centralized, people are going to eventually adopt to it. They are just going to accept the fact that it is centralized just like how we accept the fact that Satoshi is hidden and might have the ability to take sell so much bitcoins in different exchanges simultaneously. Bitcoin is still centralized in small parts. Like it is centralized in a way that there's a corporation that owns the funds that you have deposited in an online wallet. Same goes for gambling sites, exchanges, etc. Basically everything that allows you to deposit on a certain website.
If bitcoin was centralized and it was known to people, it's only a matter of time before someone starts to recreate the whole thing but it will function in a decentralized way. So the spotlight would easily be taken away from the previous invention. Plus, the whole reason why people are into bitcoin is because it's giving us the freedom from the government that we wanted ever since.