Exceptional work being reblogged is rewarding to the author especially new arrivals where no one knows who they are as yet, no matter which genre used.
Over using I agree can become a nightmare when searching for content, sometimes if not on similar timeline does require personal visit to people you enjoy.
Do you go seek out someone who you have previously found to bring great quality?
Excessive reblogging is spam, plain and simple, most certainly when the quality of the reblogs are low.
Quick and easy to switch reblog off to find fresh content.
Sometimes I do notice unique reblogs from members I follow finding hidden gems. Always 50/50 call on people abusing, who knows objective behind the thinking.