[Maédhros]

Melkor, like Feanor, certainly becomes interested in the beautiful thing created, but each of them wants to use it to prop up his own glory, and it is this that estranges each of them from the Valar.

There is a difference of course, while Melkor coveted things not made by him, Feanor created them. Feanor really had no equal in the arts of crafts.
A point that is also missing is the responsability of the Valar in this.

Then Manwë granted him pardon; but the Valar would not yet suffer him to depart beyond their sight and vigilance, and he was constrained to dwell within the gates of Valmar. But fair-seeming were all the words and deeds of Melkor in that time, and both the Valar and the Eldar had profit from his aid and counsel, if they sought it; and therefore in a while he was given leave to go freely about the land, and it seemed to Manwë that the evil of Melkor was cured. For Manwë was free from evil and could not comprehend it, and he knew that in the beginning, in the thought of Ilúvatar, Melkor had been even as he; and he saw not to the depths of Melkor’s heart, and did not perceive that all love had departed from him for ever.

The Valar, Manwë was deceived by Melkor and it allowed him the chance to poison the minds of the Noldor and make them proud.
Fëanor, because of his uniqueness, was the most that was affected by it and because he was the target of Melkor's lies.

Then Melkor lusted for the Silmarils, and the very memory of their radiance was a gnawing fire in his heart. From that time forth, inflamed by this desire, he sought ever more eagerly how he should destroy Fëanor and end the friendship of the Valar and the Elves

The lack of foresight of the Valar (Manwë) had terrible consequences for the Elves and ME in general.