Personally, I thought it was finished long ago but it may be that I just got bored with it and just stopped watching. Sure, At first, It was entertaining but when so many people knew his true identity (friends and foes) it's hard to believe it would still be a secret. They say you only miss people when they are gone but that's not the case when they have overstayed their welcome. What I think killed it for me is when the series become as predictable as Scooby Doo. Getting rid of this series would just open up the slot for something else, Maybe even something much better.
Many people think the flash is getting old but what I say to that is there are many fans many people make magic but there is no one that can replace flash as he is more popular than Ben 10 the new Ben ten the new one is so idiotic