Bitcoins is not yet a legal currency cause not all countries, world bodies have accepted or recognise it. You wrote so much and how come you fail to understand that this coin cannot be controlled by anyone, no one can manipulate it and most of all governments cannot find out who owns it or make you pay taxes. There is a huge hassle process and it's expensive to track it, make a whole set of laws. You get the point don't you.
I agree with the term "not 'yet' legal" whereas it implies that soon enough the bitcoin will become legal nd the government will accept that they can not really control bitcoin because of its decentralized system. W
The users can assure that with bitcoin there money are safe without tax. The government can legalized it if they will implement rules or laws regarding to it.