The general consensus for content like Throne of Thunder is that the next raid was released too soon, there wasn't enough time to complete the content, and that the next raid should have been released later.
But isn't that situation a good thing? Shorter raid tiers mean that fewer people will completely finish the content and always have something new and fresh to do. And people who finish the tier quicker will have the next tier's of content sooner. If I had to pick between 6 month raid tiers and 9 month raid tiers, I'd pick 6 month raid tiers every single time. And so would the many people who simply do not raid for every single week in the raid tier. So I think the solution here is to release content faster, not slower.
The notion that "raid tiers need to be spaced out better so we don't have content droughts" is a self-fulfilling prophecy. The more you ask for longer raid tiers, the longer these expansion waits will be. And also if WoD has shown us anything, this thought process is completely irrelevant. No amount of spacing out would have made the lengths of the 2 raid tiers in WoD acceptable.
I think that instead of actively petitioning Blizzard to release content slower, we should be asking them to release content faster so that there's always something to do for everybody, and to not keep people waiting for months on end without new content. Not only will this benefit the playerbase, but it will also benefit Blizzard's bottom line as people will stay subscribed for longer.