I bet a lot of the advocates of these block chains would claim that the lack of sophistication and cumbersomeness was an advantage.

You'd say things like "if it ever caught on in a big way, what's to stop banks or even governments issuing block-denominated securities, causing inflation? Would people put blocks in banks for safe-keeping, where they'd just end up recreating the fractional reserve system you claim these blocks avoid?".

And advocates would say "no, that won't happen, people would like to keep a hold of their own blocks, no-one would want an IOU from a bank if they could physically hold their very own block instead".