Is the 2016 'Ghostbusters' film one of the worst remakes ever?

Answer 1

This is a subjective question, but judging by critical acclaim, no, it certainly is not.

It's got a respectable 73% on Rotten Tomatoes compared to the original's 97%. In fact, its score is significantly better than Ghostbusters II (50%).

If you're looking for the "worst remake ever" here are some much better candidates:

Planet of the Apes (2001) - 45%, original 90%
Psycho (1998) - 37%, original 96%
Sleuth (2007) - 36%, original 96%
The Longest Yard (2005) - 31%, original 81%
Arthur (2011) - 26%, original 90%
Fame (2009) - 25%, original 83%
The Day the Earth Stood Still (2008) - 21%, original 94%
The Wicker Man (2006) - 15%, original 90%

Answer 2

If you believe it was then Yes, it was.

It was considered a flop based on the budget & amount spend in promotions compared to its box office take.