Partially clearly you are correct but regardless those who have bought Blocknet now and in the past believe it to have some future and are rooting for the project to succeed that we can certainly agree on.
As I have said I am just a noob and dont understand half of it lol but :
I like the idea of owning a node.
I like the idea of it being exclusive yet "accessible".
Say you have 20 guys ending up owning all the nodes there would be no real difference between an centralised exchange today and a decentralised in the future basically.
But as Synechist commented I believe this is an issue being taken into consideration.
Even in the far fetched scenario where 20 people ran the nodes it would be very very different from a centralised exchange.
Many people owned xc. Many people owned block.
I think the number will eventually be around 3-4k to run a SN but 5k is fine.