and a coin with 1mb blocks forever has economic viability?
Have you noticed that since around the time of the segwit2x intention signaling that the bigblocker nutjobs discontinued spamming the bitcoin network, and the mempool backlog has reduced to almost nothing?
Accordingly, transaction fees have reduced to like $.15 or less per transaction, and transaction times are back to normal times of less than an hour (frequently within the next few blocks, which would be less than 30 minutes if 3 confirmations are required).
Furthermore, after the bigblocker nutjobs indicated that they are going to fork into bitcoin cash despite the pretty much guaranteed locking in and activation of segwit, transactions on the blockchain had increased incredibly - likely due to folks moving their bitcoin's off of exchanges because of the threatened imminency of a hardfork - however, in spite of the considerable increases in on block transaction volume, the mempool has continued to remain without much of any backlog - resulting in ongoing low transaction fees and fast transaction times.
So, yeah, maybe at some point in the near future, bigblocker nutjobs will continue their spam attacks on the bitcoin network, but for now it seems that they are aiming their energies at preparations for their proposed hardfork.