As far as the UK parks are concerned, it isn't a recent thing. In my opinion the parks have never been managed as well as they were back in the 90's in the early Tussaud's days when we saw such high quality additions particularly at CWoA and AT such as Transylvania, Mystic East, Katanga Canyon, Gloomy Wood, Forbidden Valley. These were highly themed areas with some great attractions that still stand today.
Even the smaller coasters back then were heavily themed, the original Rattlesnake themeing was amazing with animatronic Mexicans, rattlesnakes, caves, the queue was a delight. Over the years though we have just seen it all removed or left to rot. Its such a shame.
The best area Thorpe ever got anywhere near the quality of those I've mentioned was Amity Cove.
In the later Tussaud's days they eventually stopped investing so heavily in themeing and we ended up with Air hardly themed and not fitting into Forbidden Valley etc. That was the start of the decline..
Tussaud's was at its worst when we saw Spinball and Rita literally plonked down with no long term thought at all. Just to keep gate figures steady and AT still suffers with a Dark Forest theme that was never really going to work with Rita racing through it, and Spinball looking ugly in front of the towers with plans to move it elsewhere still in the pipeline.
Merlin have since came in and are still an improvement on those late Tussaud's days but have never reached the heights of those early Tussaud's days. They have tried with areas such as The Swarm island, Wild Asia, Dark Forest but these are just no where near the same quality despite their best efforts.
It also seems like they are now giving up on investing in CWoA altogether if they don't plan on rethemeing Dragon Falls and actually removing it. Starts to stink of the late Tussaud's days of just keeping gate figures where they want them with minimum investment.
Where the parks are currently heading, who knows? I'm not sure Merlin even know. But as long as they keep their profits up whilst basically monopolising the UK industry, I'm sure they will continue to run the parks how they are at the moment. Which looks like there are no real long term plans in place at all and decisions are made short term.
It is just annoying that we have to accept that we will never get anything on the same quality as Disney or Universal whilst Merlin are running the parks. They just don't seem capable of doing it. That's why most of us suspect the dark ride for Thorpe isn't going to be very good at all.