This doesn’t feel like an accurate statement. It’s probably better described that Mozilla funded it as a research project, realized that it was going to cost a lot more money and time to bring it fully to the market and decided to save the money (and distributed that money to execs and others in ways that were not inline with their projected morals).
Based on what I’ve read from their blog posts, Mozilla then took what they could from Servo and incorporated it into Firefox, which means they were able to get some value from the project.
My guess is that if someone were to have offered Mozilla a lot of money and an unlimited timeline to complete Servo, they would have done it.