The logic sounds simple, however I think this won't be the case. Even if it becomes a reality and kin will be the most used currency, it certainly won't appreciate tremendously in terms of price. Just compare the 21m Bitcoin to the 10 trillion kin. It's not a good investment imo, however I also hold a bit of it, just in case something unexpected happens.
Price is driven by demand and supply is irrelevant to your potential return on any coin. I'll get to the math but for now I'll explain the main concept for this supply.
KIN wants to be a micro transaction token. It will be used to reward users of an app, as a currency to buy items or unlock features in an app, or even as a tipping token. You may be thinking that any coin can also do this, which is kind of true. However, you have to keep in mind KIN will be used by 100's of million of regular consumers. Not just 6 million crypto trading speculators.
Yes, I can send 0.0000014 BTC if I want to send a $0.01 micro transaction. However, if you include the fee to send Bitcoin, then it really didn't make any sense because the fee cost is so much more than the $0.01 you were sending. Kin's blockchain will allow you to send that $0.01 without a fee that makes the transaction pointless.
Now you might argue that there are other coins out there that have a very small sub penny fee that can be used this way. This is also true, but where the 10T supply proves itself. Lets say this other coin is also 0.0000014 XXX to send a $0.01 micro transaction. Pretend you're a consumer who has no idea about crypto, but your favorite app just integrated this coin. It might be very confusing why you're sending 0.0000014 of this crypto. It's such a small number and nothing like what they're used to in the real world when paying in integers or at most two decimal places.
Since KIN has 10T tokens it will always use "comfortable" numbers for these non tech non crypto main stream app consumers. Say KIN is $0.001/token. In order to send someone $0.01 I would make a transaction for 10 KIN. This is a much cleaner number to handle micro transactions. It will make much more sense for the consumers. KIN isn't geared towards the current users of the crypto space, they're going to bring in a flood of a new type of user. Making the entire process (speed, fees, usability etc) as easy as possible for them will be the key to success.
Now for the math
Yes, supply is important as it can affect the price of a coin. However, the most important thing about the supply is that it isn't infinite. As long as your coin has a hard limit on the total coins that can ever exist, then supply is relative from one coin to the next.
I'll be using Bitcoin and Kin in this example, but will use made up prices to keep the math simple and make it easy to follow.
Bitcoin
Price: $476.10
Supply: 21,000,000
Marketcap: $1,000,000,000
KIN
Price: $0.000100
Supply: 10,000,000,000,000
Marketcap: $1,000,000,000
Your claim is that KIN can't appreciate or won't appreciate because of it's drastically higher supply. Again, supply is only affecting the price per coin. It has nothing to do with how much a coin can appreciate.
Yes, KIN will never be able to hit $476.10/coin, but it doesn't need to. It doesn't make sense for it's purpose and most importantly it doesn't dampen the ability to make money on it.
If you had $1000 and could invest in either coin based on the numbers above what would you pick? Would you honestly base it on the total supply? That just seems silly... You would pick whatever coin has the most potential to increase in value. I'm not saying increase in value as far as the price per coin, but as a % from where you invested. Supply is completely irrelevant.
$1000 into bitcoin would give you = 2.1 BTC
$1000 into kin would give you = 10,000,000 KIN
Now let's say the demand for both coins were equal over a period of time and they both doubled up:
BTC = $952.20
KIN = $0.000200
Do you honestly believe that because you're holding Bitcoin with a lower supply and the fact that it's already over $900 makes it superior to someone who invested in KIN? Absolutely not, it's all just relative. Both investors would be sitting at $2000 in value.
Yes, Kin will never be able to hit $20,000 a coin like Bitcoin just peaked at, but it will never need to. Kin's success will be based off a much smaller number. a 10,000% gain on an investment is a 10,000% gain on an investment. It's as simple as that. The per coin or per share value is irrelevant. You'll just end up with a higher amount of the less per coin or per share value option.
Demand will have the same affect on any coin. The only difference is you'll be trading millions of Kin vs fractions of bitcoin. You're not going to just buy 2.1Kin and complain that it will never be worth $40,000.