If it's not 'in your face', just pretty close, then a lot of the droplets will be too small for the simple surgical mask to filter out. Especially as it leaves a lot of gaps around your nose and mouth. Not to talk about your eyes, where you can get infected just as easily. (Yes, you could wear protective glasses too.)
But... if almost everyone wears these in public places, which actually just became compulsory in Czech that should give pretty good protection to everyone (by filtering the emission of the asymptomatic infected).
And if we think about this use case, then actually it makes no point telling people that it won't protect them because if they think it will they are more likely to wear it.
If a surgical mask can stop germs from going out of the mouth, then I better hear a more rigorous reason why that same mask doesn't work in the opposite direction.
One word: leakage.
Watch this:
Healthcare - Mask vs. Respirator Video - 3M Worker Health and Safety