Why did veterans of Gaius Marius remain loyal to him after their military service?

Veterans of Gaius Marius remained loyal to him primarily because it was in their direct personal interest to maintain a close alliance with their former general.1

Following his recruitment reforms, which allowed him to enlist volunteers from outside the traditional propertied classes, Marius became a powerful advocate for his soldiers' post-service welfare. He utilized his political influence to push for legislation aimed at the settlement of veterans, including bills for land distribution and the establishment of colonies. By securing these benefits, Marius created a system of mutual reliance where his veterans provided him with significant political support, effectively demonstrating the influence a successful general could wield through the votes of his former troops.123