Why is a person blamed for not marrying, and why do some of his female relatives look at him with schadenfreude and demand that he strive for it, even though marriage is decreed by Allah and predestined, and we have supplicated to Him and humbled ourselves before Him as He commanded us in His saying, "Call upon Me; I will respond to you"?

Marriage is one of Allah's decreed destinies, and belief in divine decree does not mean abandoning legitimate means. Repeatedly rejecting suitors and exaggerating conditions is a path with undesirable consequences. One should employ legitimate means, increase supplication with good expectations of Allah, and not hasten outcomes. There is no harm for a woman in offering herself to a righteous man, within stipulated guidelines and manners. Allah's decrees unfold with His wisdom and mercy. Allah may divert something a servant desires and store for him something better, due to the servant's ignorance of what is truly beneficial for him.