No, it's fear of success. "If I do well, they will expect more of me, and I don't want to deal with taht, however if i fail or only do OK, they will leave me alone". It is fundamentally a fear of others expectations.
In some particular cases - yes, you are afraid of going too high because the fall would be most painful. But still there may be, for example, some (latent or not) religious fears of too much wealth.
That sounds like Freud, who is pretty much discredited on everything. There's really no evidence for "latent" or "subconscious" processes that are analogous to conscious processes, such as fear. Fear is always pretty damn conscious.