I don't think it was spam at all.
With the EDA kicking in on Bitcoin Cash the hashrate dropped a lot and same time the markets was pretty crazy what just caused a lot of transactions.
It was growing all the time and dropped a lot short before the Split on 1st August.
https://blockchain.info/charts/n-transactions?timespan=all&daysAverageString=7Increased then when Bitcoin was reaching all time highs and then when the fees spiked the amount of transactions decreased again.
It makes no sense that spammers spam a lot when its very expensive but then stop when its cheap. They would start spamming when its cheap and if it would be miners they would just continue spamming low fee transactions to collect higher fees on normal transactions.
With now lower fees the amounts of Transactions is growing again slowly, probably soon the cap is reached again and then the fees will increase a lot again.
High fees causes less transactions, low fees causes more again but lot users will stop using Bitcoin for good as well when they had to pay high fees.
The first time the tx fees spiked for longer Bitcoin lost a lot of market share that made them lower also again.
It was also a time when Bitcoin price increased and was so more used.