I'm gonna have a stab at this and say that it wasn't spam.
-snip-
You want to tell me that the tens of thousands transactions in the following format: Address A -> Address A
Are real financial transactions?

It is most certainly spam.
ah.. lol.. ok.. That is pretty obvious..
also do you see in the second picture, the second red arrow with an exclamation mark in it.
an straight line with a fixed-rate-increase of number of transactions is not normal. and this is just a small scale, if you look at precious times you can see the bigger ones

~
They might not be real financial transactions, but they may be transactions that utilise the blockchain to store immutable data. That may or may not be spam depending on your viewpoint.
although, it is hard to believe about some of these txs but i agree. we can never easily brand transactions as spam, but most of the time when you see someone is sending multiple (100-1000) transactions to same address with 10 seconds intervals, that can not be normal behavior.