I'm not talking some far-in-the-future hypothesis. I'm talking about the fact that Monero's blockchain is exploding in size with negligible amount of transactions it now process.
This premise is false. You are ignorant of the fact that Monero transactions are not "negligible." You likely assume they are because: 1. Most of the shitcoins, by contrast, have negligible transctions; and 2) Monero is relatively new. In fact Monero has gained nearly unprecedented adoption and usage for an altcoin (e.g. see post #1 on this thread), although at present most of that usage is speculation. That's still usage though.
The blockchain is growing at 6 MB per day with about 3% as many transactions as Bitcoin. There is a small constant factor difference in size between the two, roughly 5x.
Upcoming changes will likely alter this factor but in offsetting directions, so I expect this to remain fairly close.
There's no PHD needed to see that with anything close to BTC amount of transactions it would making running the full Monero node unsustainable for most users.
This is also false. Moore's law will likely make running a full node (even at close to Bitcoin volumes which no one expects) less expensive in the future, not more expensive.
Wait a minute, 6MB/day with 3% of Bitcoin transactions, and Bitcoins blockchain grows at 34 MB/day, that's not 5x the growth of blockchain compared to bitcoin, it's 5.82x, closer to 6x for the same number of transactions. You want to tell me that 6x bigger blockchain is not a design flaw, and it can be settled with well orchestrated hard fork? It's not only the question of disk space for a full node to use, it's the question of node's ability to successfully verify every block with such a large amount of data. Relying on Moor's law to solve the problem is not a rational approach. But then again, who am I to advise Monero developers what's best for their coin. If you think it's just fine - great, it's your child.