Decentralised and free from control, always running
There are dozens of exchanges, and thousands of local exchangers on localbitcoins. If the biggest one gets taken out, there are plenty more. It is decentralized. Yes exchanges aren't always running, but they are up a hell of a lot more frequently than 8-5pm on weekdays. And if you want to store bitcoins yourself like cash, they work 100% of the time your internet is up.
Try spending your dollars in Europe. Bitcoins work in both places.
The fee is less than 1 cent. If you use an exchange to send, it is free.
New privacy model, Transparent system,
Bitcoin has "user-defined" levels of privacy. If you don't care, you are public. If you are careful, you can be anonymous, which is why Silk Road exists
Try paying your friend $15 when you only have a $20 bill and he doesn't have change. Try paying someone $5.932. Try paying for a candy bar with a $100 bill. Bitcoin solves this.
Secure, Fast transfers,
How long will it take you to send $50,000 to your friend in Europe? How long will it take you to send $100 from your Wells Fargo account to your friend's Chase account? Bitcoin transactions take 10min instead of days. Securing bitcoins is certainly an issue, but most people understand 2-factor authentication. Bitcoin is digital cash. It can get stolen from your wallet just like physical cash. It is not the job of the currency to keep itself from getting stolen. The bitcoin protocol is secure.
Chargebacks are good when a physical good has been shipped. Where wire transfers and Western Union are used, chargebacks are not desirable, so they are irreversible. The advantage of bitcoin is that escrow services can be built on top of it.
Environmentally friendly / efficient,
It is certainly true that mining uses energy to secure the network. But bitcoin is more efficient than digging gold out of the ground, transporting it around, and storing it in vaults, as central banks do.
The USD is digital. Gold is not. This entire list of advantages do not apply to EVERYTHING, but most of them do. Clearly you haven't looked at it very closely since 2 years ago if you think it can only be used to buy drugs. I personally find great value in being able to have a stash of money on a flash drive and do whatever I want with it fast. I can withdraw to either my UK or US bank account fast, instantly deposit it on a poker site and play from inside the US, put it on a sportsbook and make a wager for way lower vig than USD sportsbooks at btcsportsmatch.com, donate $1 to wikileaks or my current favorite charity myrefugehouse, cross a border with over $10,000 worth without declaring it, pass through a metal detector, trade it to someone for cash in most major cities on localbitcoins, remit money in 45 different currencies, and order up stuff from 10,000 stores (or get a huge discount by trading bitcoin for gift cards). I also get paid 5% to cash bitcoins out to my prepaid debit card by buying moneypaks from idiots. I can do this with fees approaching nothing, the IRS doesn't know about it, no one can sue me to take it, my wife doesn't get half of it in a divorce, and I don't have to worry about it being printed away by the government. On top of all this, my money becomes worth 1000% more per year. According to the survey on the demographics of bitcoin, far more people have used bitcoin to make donations than to buy narcotics. Bitcoin will behave as an investment and deflate massively until it reaches its target market size. Then it will behave in a slightly inflationary way for several decades in the same way gold is.
Most public domain software is free, at least at first glance.