on this link you will see BCH vs BTC, it looks like Roger Ver always says in his tweet every day always comparing the transaction costs and transaction speed, so I'm not accusing anyone who is spamming transactions on BTC and ETH for some time, if not for competitors , once again I do not accuse anyone here  

What if spend a huge amount of BTC just to congest transactions just to make fun of it.
I think it's possible mostly if the attacker holds large amount of BTC

This is a non issue. It's exactly what people should be doing with their small inputs at a time when fees are low. Like the article said that the average fee wasn't affected, the only thing different here is that there shouldn't have been any empty blocks mined - They all should have had transactions available for miner fees. Some pools still mine empty blocks though so this period should have been an eye opener for those miners.

In the end if you needed to get a transaction through, you really just had to set it at a 2 sat/byte fee, then your transaction took priority over these. That is unless a pool was choosing these transactions in the blocks they mined. This could happen if they were consolidating or something, which is perfectly fine. The problem before was people congesting the system at their own expense with high fee, low value transactions. This does congest the network and cause people to pay more to get their transaction confirmed asap.

yes it seems right that you said there are a number of groups that deliberately send spam to the bitcoin network.

I also think a spike like this also means the bitcoin protocol is threatened because the speed of shipping transactions is not confirmed as usual, maybe also with this confirmation jam, of course the price will also be low.

Bitcoin is working as expected. You're welcome. 

maybe that's what causes altcoin prices lately tends to decrease, if this incident continues to repeat whether people will leave bitcoin, because no one likes problematic and slow transactions, I hope this problem passes soon, so the price of bitcoin can go up again.

This has not been the cause of altcoins decreasing - there is no cause and effect here.

My guess is that all that is happening is that an exchange decided to consolidate all their dust transactions. The problem will disappear shortly.