1- the decentralization is being destroyed a day after day by big mining pools and exchanges and wallet services and all kind of other centralized services.
2- in fact, Bitcoin is a high inflationary currency at this moment (for the next 100 year Bitcoin will be still inflationary), 25 BTC are mined in average of 10 minutes, well in fact it has been
7 minutes for some time now to be accurate, but lets pretend that is 10 min instead so: 150
BTCan hour or 3600
BTC a day or 1314000
BTC a year, yes more than a million Bitcoin... this makes the inflation rate more than 10% a year.
3- not really easily stored, you need to be so careful when dealing or storing bitcoins,
many thefts and hacks were going around the last 5 years, many exchanges and services failed because of this, sending looks simple but for a person who is not so tech savvy it looks so complicated a combination of capital/small letters and nembers as an address and change addresses and backups and.... add to that in order for the network to work(transactions being confirmed) miners are needed so there so much energy needed to spend (secure/confirm the validity) a bitcoin.
4- not anonymous, I would say it could offers some kind of privacy if you know how to use it, it sure offers insurance against identity theft but right now if you send me a transaction I could see the history of your transactions and maybe even how much funds you do carry around .... when the coinjoin will be implemented and it starts working as it should or maybe when a good mixer is used this would be a real private, but now it is not anonymous neither private to be honest.
5- what you do you want me to add here ?
My main point was that "hoarding-only" currency has a right to exist.
As to the reasons to exist, your countering of these reasons is valid. However, what are the current alternatives for hoarders? Fiat and commodities, right? Both, imo, considerably worse than Bitcoin.
To clarify the strengths of Bitcoin in this context:
- Decentralised as in "not controlled by a goverment"
- Non-inflationary as in "supply increasing to a known finite number"
- Easily stored and transferred in relation to commodities such as gold or land
- Anonymous as in "hopefully in the near future"

- you continue... err... maybe here I wanted you to add that Bitcoin is fun
Now, I fully agree with Mervin that better cryptocurrencies than Bitcoin will emerge or perhaps emerged already.