Good for you! In a society in which every participant gets a trophy and protecting others’ self esteem often transcends an honest critique of their work, it’s often up to people in your position to draw the line and say, “This needs more work and here’s why.” Acceptance into a professional or academic training program is not conferring a degree a priori. It is just the beginning of a rigorous training experience. Of course, there are examples of narcissistic, tyrannical major professors who make the PhD degree seem like an unattainable mirage, but these are just bullies who chose academia as their platform for punishing others for their emotional traumas. Plenty of those in the corporate world too!