1.) It is very important for blockchain networks to be high availability because it ensures a 24/7 365 approach making them always available.
2.) The internet with thousands of server and computer’s running all the time globally enables blockchain networks to have such high availability.
Bitcoin exchanges are highly available 24 hours a day , 7days a week ,which along with the world wide network made up of Nodes cannot be shut down unless there was a complete
power failure
this availability to access your money any time makes this service invaluable and more user friendly than banks .
Why is it important for blockchain networks to be high availability networks?
So the decentralized market place engine can be alive all day and night. Availability is global and there are many different time zones. When It night time by me it’s day time elsewhere so gaming, trade and commercial activities etc., needs to be continuous.
What is it that enables blockchain networks to have such high availability?
The key here is mining. This brings a level of security to the market and allows the continuous traffic of transactions to be conducted.
Hl Wxdoc,
Thank you for your post, because in my reply to " High Availability" homework I did not address business and market advantages of 24/7 availability , which like Bank access is equally important , so thanks again 
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It is important for blockchain networks to be high availability networks because it has to be up and running 24/7 and 365 days to verify transactions and add them to the ledger.
Miners enables blockchain networks to have high availability.
It is a global network and so users need to be able to transact on it all the time.
Incentivisation. The more computers leave the network the more lucrative it becomes for other computers to join due to drops in the complexity of the POW puzzle.
1. Why is it important for blockchain networks to be high availability networks?
A global network needs to be open 24/7 365 days a year to enable anyone in the world to access it and Blockchain achieves this.
2. What is it that enables blockchain networks to have such high availability?
Blockchain is able to achieve high availability through incentives or block rewards given to miners. These rewards are automatically adjusted depending on the demand of the network
It is important so that transactions and updates on the blockchain can be added at any time of the day of the week or the year. This makes it very useful to users because they don’t have to wait. It makes applications quick and efficient and reliable.
The blockchain has high availability because the nodes on the network (at least a large portion of them) are always connected to the electricity and internet and the network. Even if some of the nodes lose power and are turned off, the network can still run because there are other many nodes that can continue verifying updates to the blockchain and also new nodes may take the place of the nodes that go offline in certain circumstances.
Because it is a decentralized, global, uninterruptable reliable infrastructure which is accessible to everyone with an Internet connection, 24/7 for 365 days a year. Downtime would equal the Blockchain network being useless.
The miner’s model with their monetized incentives; the miners assure the network to run 24/7, 365 days a year and even when one stops a new miner joins the network to assure the network plus security remain strong Uptime and covered.
Because it needs to store large amounts of data on a wide scale of the network
The character of multiple independent nodes conforming the network.
Question 1
It is very important for blockchain to be highly available because it is used globally. It is a network that is bringing the world together and has to be accessible 24/7, 365 days.
Question 2
Blockchain network is highly available because it is decentralized
Homework on High Availability - Questions and answers.
Why is it important for blockchain networks to be high availability networks?
for globalization and incentives in the network.
What is it that enables blockchain networks to have such high availability?
People making money through incentives - 24/7 X 365 - WHICH IS LOVELY!! 
1.Why is it important for blockchain networks to be high availability networks?
it is excaly like a centeral database so it need to be 24/7
2.What is it that enables blockchain networks to have such high availability?
Incentive give everyone wants money or reward.