Why did the lightning network implement a gossip protocol? As pointed out by many lightning developers in the past (e.g. Rusty's 1 million channel challenge) the gossip protocol is quite noisy and a part of the BOLTs causing many engineering challenges.

Today, I learned that Ethereum's Raiden network does not have a gossip protocol. Since all channels in Raiden are smart contracts that live in the Ethereum blockchain, Raiden nodes are supposed to learn about the network topology by looking at the Ethereum blockchain.

I believe funding transactions could have been designed to store information about Lightning nodes. Why was that not done? 

Reasons I see:


With our design we can have private channels
blockspace is valuable, so we did not want to store more info on chain than necessary
we needed a transport and communication protocol between nodes anyway, so why not add the Gossip protocol?


My feeling is that there must have been other reasons for that design decision. So what am I missing?
The main idea of Lightening Network is to make the Transactions as fast as possible and to solve blockchain Network scalability issues. Whereas the main essence of the Gossip protocol is that each participant randomly selects a peer and exchanges state. As it can be seen that  Gossip approach is converging in O(logN) gossip rounds where N is the number of participants. Whereas communication on off-chain Network is only O(1) hence reducing the space on the blockchain. Applying Gossip protocol to the lightening Network on defeats the property of 'Lightening' and makes the network massively less scalable. Hope you like the answer.