The big hype was always due to the ability to shed large oracle based data warehouses. When Hadoop was full of hype in 2010 Oracle was charging 150k/cpu core/year for a rac cluster license.

Considering that oracle is not in fact magic, this meant that a large number of firms were spending 7-8 figures annually on oracle licenses. Map reduce/Hadoop was the first accepted alternative that didn’t involve spending outrageous license fees and instead involved outrageous hardware expenditure.