I used to have similar experiences from my mother, who was a semi-professional photographer herself, where she would edit my pictures and suggest crops. She never meant harm, she just thought her vision of what my picture should be trumped my vision. I don't do FB or any of those other sites, just because often (but not always), the people most active are the people you should listen to the least.

The question really is, did you like the picture? Does it convey what you want it to say? If the answer is not yes, then you have work to do. As soon as you stop caring what others think of your photos, you take the first big step to developing yourself as an artist. Asking for advice from the crowd gives you pictures that look like the crowd, which is exactly what the artist is not. I have no problem asking for technical advice or equipment advice but I will never ask for advice on artistic vision. If I need to ask others what I should say or convey, then I am no longer speaking and my pictures will reflect that.