why do I feel like they are just making a small problem bigger than it should? Or am I not...

The whole problem is that Diana does not acknowledge her mistake and never have regretted yet about her wrongdoings. If u notice it hestia hasn’t done much. At the end of the day everything that happened to Diana was all consequences of her own choices, hestia was only pinpointing and making people notice Diana behavior( tho she didn’t do much cause diana showed everyone her true colors fast).