Do you think the internet is centralized because you need to rely on business grade ISP?
Yes.
In fact, until we have a worldwide wireless mesh network in place, Bitcoin is vulnerable to this centralization.
This is overly paranoid. This would be a good thing if we ever get there but it is not a reason to not move forward. If we can't move forward because the fear of the unknown then no one would ever walked on the moon.
The unknown?
ISPs every where all over the world are currently censoring internet access to their customers in some shape or form.
The internet grid is owned by major fiat corporations who can easily be pressed into "interfering" with a growing government threat.
While it may not happen in your country, it will in several others. We need to make Bitcoin resilient to these attacks.
Exactly. There are a lot of sites blocked where I live, and I have to use Tor at times. Tor is what gives me freedom, so does Bitcoin. Bitcoin is Tor of money (even better!). Having Bitcoin 'decentralized' as modern ISPs is only in my nightmares.