Haven't seen the film and don't want spoilers? Best not read further.
All right, so: Different people have different ideas of whose fault the disaster was, if there was anyone to blame at all, but I've felt since seeing the first five মিনিট of the movie that it's their parents' fault. Without a question.
Elsa was controlling her powers just fine until a moment of fear for her sister's safety during playtime caused her to accidentally strike her. While আপনি can blame Anna for goading her sister into playing with her when she wanted to sleep, and then put herself into danger দ্বারা expecting her sister to keep making snow pillars under her as she kept jumping faster and higher, and ignored Elsa's desperate pleas for her to slow down, which is what caused Elsa to panic and strike her out of fear... আপনি can also say that Anna was a little girl that didn't know any better. Yes, it almost cost her life, but it was also an accident. Not even a fatal one, as her parents knew trolls that could cure her. Surely then, after getting better, she could learn from her mistake, her parents could teach her to be আরো cautious, and they could play আরো safely in the future.
No? Well, this is where I think the parents' blame comes in.
Rather than treating the situation as the accident it was, and later asking their daughters what caused it so it wouldn't happen again (maybe ask Elsa on the way and discuss with them after healing Anna, obviously), Elsa's parents preemptively decided that her powers were getting out of control, she had to stop using them entirely, and hide them from everyone entirely. Worse, the trolls warned them that fear would cause disaster, so of course they do the exact worst thing possible and constantly drill fear into Elsa while simultaneously telling her not to feel anything. That's like adding fuel to a আগুন and then telling it not to burn.
While আপনি can argue the parents couldn't have known how well Elsa used her powers with Anna when they weren't around (the whole room was covered in snow and Anna was hurt when they came in, so I guess it looked like her powers were losing control), they also did not ask. What's more, Elsa had much আরো trouble controlling her powers AFTER they started "helping" her than before. It was like the shut-off valve to a gushing water pipe had been ripped off, as she couldn't keep the ice from forming without intense concentration, where before she could turn it on and off with ease. This should have probably been a big hint to her parents that their method of isolating and fear-mongering wasn't working, but they kept doing it anyway, for years.
It doesn't take a genius to figure out what eventually happened. The trolls warn that fear will make her lose control in the future. What do they do? Constantly drill fear into her. Her fears and powers are getting stronger. What's their answer? Tell her to keep them bottled up so they keep boiling under the surface until the smallest trigger causes them to come blasting out. She needs to control her emotions and powers. What's their answer? Constantly make her feel like she has no control over herself, her emotions, অথবা her powers. Like the pressure valve has been destroyed. That she either has to dam up her emotions and powers completely, অথবা they'll both erupt like geysers. No in-between.
Not only that, but they completely isolate Elsa and keep her dependent on them to coach her every সেকেন্ড of every day. This predictably emotionally crippled Elsa, making her feel like she had no control over herself, and relied on them for everything. She even asked them not to go, fearing what could happen. They left her anyway, and guess what happens? She's alone and doesn't know how to get on without them.
আপনি can argue that Elsa chose to continue to her parents' method of shutting her emotions, sister and world out, but years of isolation and fear-mongering are not easily wiped away. When it started, Elsa was a child that didn't know any better, and her parents kept her alone and in a state of fear and powerlessness for years. They literally raised her to think she could not feel অথবা do anything lest she cause harm like the night she almost killed her sister, that she could not share অথবা tell sister anything lest she nearly kill her again.
Anyway, আপনি can make the argument her parents didn't mean to make the situation worse, they did it because they loved her, wanted to protect her, did what they thought was best for her, yadda yadda yadda. I still say that drilling in fear after being told that fear would make it worse, that the fact that she had much আরো trouble controlling her powers AFTER they tried to "help" should have told them their methods weren't working.
