I find that tears just start to well up in my eyes when "X" emotion(s) become too much for words. I am essentially overwhelmed and the only way to express the feeling is with tears. I no more have control over the tears forming as I do the emotion(s) rising. If I can manage to control the emotion, then I manage to control the tears.
I don't know that having emotions, or not, can be considered weak or strong.
Vulnerable, perhaps, might be a better term. When I am crying I do feel quite vulnerable, and I do not like that feeling.