It's a great movie and a really damn impressive note to start your career on. I mean, David Lynch made the thing in his 20s, on a budget of 20,000$, over the course of 5 years. He delivered newspapers to fund it. He lived on the set. Jack Nance had that ridiculous haircut for five years.
But even putting its history aside, the mood it creates is fantastic. Almost no other movie really captured that feeling when you're suffering from depression and anxiety to the point your almost paralyzed and everything around you, even the most normal situations, places and people suddenly feel oppressive and overwhelming. Between that brilliant sound design that never lets up, the sets and effects that invoke some pre H.R. Giger corrupted industrial dystopia and Jack Nances constant look of understated terror, it's, despite all its abstractions, extremely relatable to everyone who ever felt alienated from the world around them.
The plot is pretty simple, especially compared to Lynch's later movies, but there's definite substance here. There is a lot of commentary on American family values in there and at points the movie downright satirizes the typical media portrayal of the American family in productions like Leave it to Beaver or Father Knows Best that, I imagine, Lynch grew up with. There's a lot about sexual anxiety, early adulthood, parenthood, the alienation of the common man in industrialized society, poverty I could go on. Hell, I still think there are some strong Christian overtones to the movie, but I may be imagining those.
Either way. Eraserhead is a good fucking movie. Your friend is full of shit.