People who act like they’re above criticism are ridiculous.
Yes, there’s a difference between constructive criticism and flaming. It’s not even hard to tell the difference because the wording and intent are pretty much the opposite.
Flames seek to damage the ego of a content creator and make them feel bad about their work. Constructive criticism helps them improve on their work so that it’s better later on.
You don’t have to take all constructive criticism. If you did that, you’d be constantly changing your work and that would be impractical and might even ruin it. But at least think about it when you receive it. Why would someone take the time to let you know what you might have done wrong so you can do a better job? Talk it over with others. Thank the person who was polite in pointing out mistakes you might have made. Yes, even if you don’t plan on taking their advice.
Content creators in fandoms who act like their work is perfect because they worked hard on it or they think they’re above criticism really need to grow up. No content is above criticism because no content is perfect.
The only thing an aversion to criticism will eventually do is drive people away from you. Only trusting your own vision won’t end well. No matter how talented you are, you can still improve. And yes, it might hurt to hear that something you did has glaring flaws but better to fix it the next time around than to never fix it at all.