Just look at the exponentially rising number of bitcoin ATMs which are currently deplyed around the world. So your argument somehow shows that the comparisons with the early internet actually makes sense. Because at these early times people argued exactly by assuming that there is no network growth. So in the early 90th most people had the opinion that the internet is useless because there are only a few connected computers. Don't underestimate network effects and exponential growth.

Of course nobody knows at the current point where this is going. But you also cannot make arguments ibn which you are assuming there is no growth. Of course the price could go up or down but it is really hard to imagine that it would go to zero.

I have no statistics about it, but I personally think that most people who are once in possesion of some bitcoins will not sell them all, but will always keep a few of them. So the growth measured in number of users seems to only increase. I would consider a net decrease in the number of users as very unlikely as long as there is not a better technologically advanced replacement for it.

There isn't a lot of reality to the idea that bitcoin is "hard". There is such lack of clear one page explanations to get started that people who don't feel like figuring it out are left in the dark thinking bitcoin is wizardry. It's not, that's why we're all exited about how SIMPLE it is. You have 2 numbers associated with your wallet. You send with one number, you receive with another. You protect those numbers like you would your actual cash filled wallet. That's it. If you can understand the grand system of calling someone on your cell phone, you can grasp Bitcoin.

It's safer to buy Bitcoin on coinbase and use those to make online payments than buying online by submitting your credit card information.

I just tried making an order on Tiger Direct which came to $137.94 and they want 0.2208 BTC. You can buy BTC on Coinbase at $628.41, so it would cost me $138.75 or a 58 bps surcharge over paying with my credit card, where I get 1% cash back, so really more like a 158 bps surcharge, plus I have to pay Coinbase immediately through my bank vs. having 30 days to float the balance on Amex interest-free.

How is it safer? I'm not giving the seller my CC info, but paying through Paypal has the same effect, and I'm not liable for CC fraud anyway. In the event that I have an issue with my purchase it's a hell of a lot easier to call Amex and do a chargeback vs. getting Coinbase to convince the merchant to reverse the transaction, or attempting to get my bank to fight Coinbase. I can also do the transaction at a set price in one step on my CC vs. buying bitcoin and incurring currency risk.

What's the upside for the consumer here?

In this example there is no upside for somebody who doesn't already have Bitcoin. But there are other instances where Paypal or other payment providers are not available or charge high fees.