You can't seriously ascribe the explosive growth from low 3k to high 13k within just a few months to adoption spreading like weed.
I agree with you there. The recent bull run was purely speculative, much like the big 2017 bull run. I would actually much prefer these bull runs not to happen, and just see a much slower but steadier and sustained price rise over several years, which would be based on growing adoption as opposed to pure speculation. These huge runs and crashes usually end in a bunch of a newbies losing a ton of money and rage-quitting bitcoin altogether
So there is no reason to disagree?
Okay then. Anyway, it is a vicious circle of sorts, in fact, it is even a double vicious circle. It is kinda self-explanatory that merchants are not inclined to accept a highly volatile currency as a means of payment but prices won't become stable unless and until speculation is massively subdued and overshadowed by adoption, i.e. when most coins are used for buying and selling goods. But there is another circle of vice which is less apparent but that doesn't make it less ugly. In fact, it makes the first circle far worse as it just adds more injury to injury
The second circle is, volatile prices discourage people from spending their coins as it makes no sense from an economic perspective. What makes sense, though, is relentless speculation by riding volatility waves. Obviously, most coins end up on exchanges, not in the wallets of merchants. This, in turn, means merchants are disincentivized further from accepting crypto as payment since there is no demand for such payments from the buyers. So the coins end up being speculated, not circulated, which adds more fuel to the furnace of volatility. This closes the vicious circle
Yes, we have a long way to go, but I do think we are heading in the right direction
Just like you can't force love, you can't force people to spend their bitcoins in a "productive" way. Economically, you would be better off exchanging bitcoins to fiat, then spending some part of the money and buying back if prices drop or exchange more if prices soar (and then buy back when the prices finally drop). You simply can't beat that, and no amount of proselytizing is going to change this simple reality
Now coming to the units, one Bitcoin is being subdivided in to 100 million Satoshis. There is nothing in between. mBTC is an informal unit, and it doesn't have a name of its own. A few names were suggested for mBTC, but there was no consensus. And we need smaller units badly now, as the exchange rates have surged past the $10,000 per coin level. Even mBTC may be too big for practical purposes now
Personally, I don't feel like we need these subunits as anything less than a few thousand satoshi (otherwise known as dust) is not collectible anyway