It can be validly used as a criticism of socialism, even if not so intended by the author.

George Orwell, also a socialist, famously noted that many of his fellow socialists were motivated more by envy and resentment toward the rich than by compassion for the poor. As others have commented, envy could certainly be attributed as the cause of many "social justice" minded policies we see today.

Those on the right would argue that (barring some virtuous individual socialists) socialism is at root an ideology for justifying envy.