Why did G-d not make the Sefirot Indestructible?

Pardon my ignorance, but I have become familiar with the scheme of sefirot and had a question regarding the interpretation of Genesis as presented by Kabbalah. In the story I was told G-d created the sefirot to act as vessels for channeling the Divine light into a limited creation. However, I was also told that many of the vessels could not withstand the flood of Divine Light and subsequently cracked and shattered. Thus, evil came into our universe from the disorder caused by this disintegration. Now, I understand that mystical traditions are often at odds with the more formal side of their religion, but this question is in regards to the internal workings of the narrative: why did G-d not make the vessels indestructible? Thank you for any answer.