Random guy here. I may be wrong, but I think you are confusing inflation with deflation. The value of BTC is rising against real goods. So in other words, it costs less in BTC to buy things today than it did last year. This is deflation.
One of the reasons this topic is so hard to debate is people using the same words to mean different things. In my post above, read inflation to mean "the creation of money" independent of prices. This is not how statistical agencies use it, but in the context of mining it's the one that makes the most sense.
Yes, as it happens, last year the price rose significantly and BTC became worth a lot more. However this is not guaranteed by Bitcoin's design and in fact this year the price has mostly fallen and thus prices have risen (price inflation). Whether Bitcoin prices are rising or falling varies over time.
In other words, you could get into a situation where people holding BTC are largely those who have spent a large amount of money mining it, and those who are speculating on its value. For those who wish to use BTC as a token of exchange for goods and services, it can be difficult/expensive to acquire in any quantity.
Miners have bills to pay and hardware to purchase, so they tend to immediately sell the bitcoins they earn in order to pay their costs. Mining is a highly competitive business with low barriers to entry (though they are rising fast along with the general level of professionalism involved), so over time profits should be thin. And this is indeed what we see.
For people who are holding bitcoins to speculate with them, all it means is that the price rises but that doesn't make bitcoins harder to acquire. The unit we call the "bitcoin" is entirely arbitrary: they are subdivisible into 100 million pieces. Satoshi could have placed the decimal point anywhere and it'd still work the same way. I've been using Bitcoin for years and the difficulty of doing so has never been lower.
In an inflationary system, currency essentially expires ..... this is an excellent feature because it encourages the use of the currency, allowing it to get into the hands of people who will use it for true growth
You're parroting the standard line sold to people by central bankers, yet under their watch the world has experienced a series of massive booms and busts. One of the most natural words that follows "financial" is "crisis". So be more skeptical!
Consider the following scenario. You have some savings in a currency with a stable monetary base, no new money is being created and none is being destroyed. Let's also say the economy is stagnant and not growing or shrinking. We would expect in such an environment that prices remain stable. Now someone comes to you and says they have a great business idea: he's going to knit little coats and put them on penguins in Antarctica, then charge tourists to visit and take photos. He wants you to invest in his business.
Perhaps you think that this is a remarkably stupid business idea that is unlikely to turn a profit, so you politely decline his generous offer. You would rather keep the money as savings for retirement instead.
Now reconsider the same scenario, but in a world where your savings are being confiscated at 2%-5% per year. Recall that due to the mathematics of compounding, at a relatively modest sounding 5% price inflation rate, after 20 years $1 has turned into just 0.35 cents: you lost most of it. Very small changes in the CPI can create huge changes in how much you end up with when you're old. In this world, you listen to the penguin pitch with interest. Sure, you think, it's very unlikely that tourists will pay large sums of money to go to Antarctica just to see slightly cuter penguins, but if you do nothing you're guaranteed to lose more than half your money. If you pay for penguin coat knitting, you'll probably lose more than half your money, but you might not. You might lose, say, only 10%, or possibly even break even. So you invest.
From the perspective of a central planner, er, central banker, this is great! Investment is happening! Employment is created! GDP goes up! But what they cannot see through the thick plastic windows of their statistics is that the economic activity their policies created is fundamentally not useful. Nobody really cares if the penguins have little coats. Heck it probably would make them overheat and hurt them. In a stable environment nobody would "invest" in this obviously stupid waste of time. But inflation makes the stupid suddenly seem like a good plan, and you get pets.com or housing bubbles.