Why is the word free a con?
If you are talking from a marketing point of view, obviously nothing is free. The word can be a marketing ploy to sucker people into some other sales 'close', or to get them exposed to some different market. Also, a company may be willing to lose money giving away free items if they can get people to buy new, different, or higher-priced products. You might get a free item, but then once you use their products, you are in essence paying for what they gave you.
If you are talking from a political or geo/political point of view: It's not a con to people who understand it. There is no such thing as total freedom. That is clear to young grade school children with average intelligence. When living in a society of hundreds of millions of people, and in a world of billions, every nation and every individual must understand many levels of compromise. Considering the many versions of oppression being advanced today, I would choose an imperfect freedom over an imperfect surrender.