Let me be clear: I'm aware that her actions, dialogue, and characterization in the games and official writing demonstrate this quality. It's just that, given what she's supposed to represent, it makes no sense for her to be against free will.
Her sphere and what she stands for are vaguely defined. She is "associated with the natural energy of living things" and "believes one should surrender will to pure passion." We at least can infer, somewhat, what 'natural living energies' means because she's so violently against necromancy.
But life energy entails a lot of positive things, like creativity, free spiritedness, joy, curiosity, adventurousness, love, and yes, passion. None of those things are compatible with a god who despises your right to free will. Things that are passionate and full of life are, by nature, free and untameable. At best what's been described sounds like a frenzy, a sense of total abandon, that would imply no one is in control, not even Meridia.
From the moment I first read these things I immediately felt that this was negative propaganda spread about Meridia by necromancers who resent her and feel like being expected not to tamper with the dead is an imposition on THEIR free will. Evil people are always complaining that expecting them not to enslave others is just as bad as being subjected to slavery themselves.
It also seems somewhat contrived- like the writers felt that since she's a Daedric Prince they had to come up with some way that being pro-life and anti-necromancy is bad. Well, I contend that there isn't anything bad about either of those things, and trying to come up with some reason they might somehow be taken to extremes veers off into making no sense at all.
Since reading her lore page, I read further and found her realm described as beautiful and full of color and light, but boring and dull. I don't believe any being associated with passion, rainbows, and life energy would be boring. Those things are too contradictory- she would have to be a Daedric Prince of illusions and empty promises, to be colorful yet dull, and she isn't. She wants people to be fully alive, to live out their natural lives to the end, and to move on in the cycle, untainted by necromancy.