Because there are times, when you have no new transactions to mine (you can see for example empty blocks with "100% health", reported by block explorers, on testnet). In that case, it is better to mine an empty block, because:
1. If there would be a rule, that "blocks cannot be empty", then miners would be forced to artificially make some transactions, even though they would never be needed by anyone in the first place.
~
I think all these points are convincing enough and has enlightened me. The number one which was quoted above, just triggered something I read few weeks back, so instead of creating a random thread for it, let me better ask it here.
So, what I came across was an article that talks about tx fees and how it can be triggered in the future. I can't find the actual source link or even remember where I read it from right now, but this is what I think the article says:
The article suggest that: in the future (maybe) when mining reward is almost diminished, miners would opt for inflating tx fees, just by creating a particular transaction, and fixing a huge tx fees in it. For example, assuming I am mining, just because I observed some little congestion, I will want to take advantage just by creating a real tx and attaching a high tx fees, inorder to trigger similar behavior from those who have their tx in the mempool.
But this trick seems to raise lots of doubts. Even if the miner successfully trigger such action thereby making everyone want to increase their tx fees, there is also a very slim chance that he would be opportune to also pick that particular tx(used in triggering the whole action) and confirming it so as to also receive the tx fee he attached, which means another miner might likely get hold of it before he does.
So, do you think this kind of approach of inflating/triggering high tx fees would work later on?
When Bitcoin first got started, empty blocks had to be seen as valid, otherwise there'd be no blockchain progress, given the lack of transactions. Nowadays they usually only occur if a block gets found immediately after another, with miners being incentivized to just get the block out there as fast as possible, regardless of whether they were already able to fill the block with transactions or not. At least it was that way a few years ago.
I think I have learnt something, as your explanations are valid.
Your second question,
from a source I read, timechain is not being used because it doesn't explain better to a lay man about how the timestamp works. For instance, blocks get added within ten minutes and the timestamp of each block is based on the time provided by the miner and validated by network nodes. Since it's not static, miners can adjust it provided it's within an acceptable time range it diminishes the reliability of the timechain initiative. (Though I'm not sure of his statement about Satoshi changing the name to Blockchain) Seems he's wrong, since Satoshi never mentioned Blockchain anywhere including this forum.
I think I also find your explanation valid. The link you shared contains nice information, but most of the articles are written in Portuguese. There is a book I saw on that site with a title:
Chronicles of the Code Keepers: Rising of Titan. Is there a way I can get it?, because it seems the website requires subscription or something.