2 - 3 yrs down the road your SSD will certainly fail, especially with all the recent SSD failures in new MAC lineup, and due to T2 security chip you won’t be able to boot from external drives unless you replace your logic board for about $1200.

Exactly, I had SSD failure on my MM2014 after about 2.5 yrs. Replaced it with the aftermarket SSD, no sweat. I was excited about MM2018 until I learned about soldered SSD. I didn’t want to do it, but it seems that the only solution for 2018 and until the next MM update is a small form-factor Hackintosh.

And what will you do when your soldered flash storage fails(because it will), like it failed on my MM2014 out of warranty. But I just replaced it with aftermarket SSD, no need to pay typical $1200 for logic board, because that’s what you will be charged by APPLE. You can’t replace it anymore on a new MM2018. Also, if your MM2018 flash storage fails, T2 security chip won’t be able to load BridgeOS, thus you won’t be able to boot from external drives. Only fix is $1200 logic board replacement. So people are concerned because we know that SSDs fail within 3-4yrs. Not everyone is buying new Macs after each update, my dual-core MM2014 is a good office machine(never mind the SSD’s failure), so the new 6-core MM2018 should work at least a decade, assuming easy repairs are possible. But they aren’t. So your “externalised modularity” is a useless gimmick. Also, haven’t you heard about the latest SSD failures in new MAC lineup, and recalls, thus people are sceptical about APPLE’s SSDs durability.