Of course ordinary citizen can use the Bitcoin. The bitcoin is open for everyone to use.
They just have to know how to use. But if they know how to use is and know all the profits of using it more people will start to use it
We are all considered ordinary citizens since we are not a military personnel, government worker, politician and thus we belong to that category. Most of the bitcoin users are or were ordinary citizens of their own state and will continue to increase in number. But bitcoins is not just limited to ordinary citizens but to all citizens in the world.
If you consider yourself an ordinary person or common person so, I think you are not making any right call. I think the main purpose of the bitcoin is to reach to the people who doesnt have any access to internet and who dont know how to use it like.
I think this will only happen if bitcoin will make its product so simple and easy to use that any human being in the world can easily understand it like any other fait or digital currency.
That day will not come, while bitcoin is easy to use at least some level of how things work is necessary to make bitcoin work for you, bitcoin is an advanced technology and I cannot be reduced that much.