Fed up of making long posts so I'll just put what I would like to say in spoiler tags. :3
When stories are done over the top I get rather annoyed too. I was worried about TP being like that, which is why I made the levels as fluent gameplay-wise as possible, in case somebody did get bored and decided they just wanted to play the levels. It means they could still appreciate the levels themselves, and if they did read the story- even better. Dark was a big improvement gameplay-wise from Destinations IMO, it's just Destinations is still my fave because of the story and amazing graphics.
Blind Experiment I ended up putting the story in spoilers and leaving it out of the levels themselves. People found it annoying switching from the story to the level all the time, and eventually I questioned if it would have been better just leaving TBE as a 'make up your own story' level, and it still would have fitted the theme. But I still wanted to keep the Sherlock story.
I will and always will still be happy to create and/or play story-driven series'. I believe they can be delivered incredibly well, despite people's negative views on them, and they have a whole different skill from just platforming. And a story-driven level can still be fun even without reading the signs, if it's done properly. Very first time I briefly played Dark I didn't have time to read the signs, but I still really got into it and ended up guessing roughly what the story was about.
tl;dr While some stories may be boring and sign cluttered, just make sure it can still be enjoyed whether or not you read it.

EDIT: GM, we're giving opinions on what makes a level fun. Platforming is about the ways you travel across the level, and heavy story levels have some relevance to that.
I've said my opinion on it now anyways. I don't think I'll say much more than this unless I feel an urge to, because there will always be people who agree/disagree with story levels, and that will never go away. I'm not gonna try and get people to change their minds about it, I just wanna make it very clear as to why I like them so much, if it wasn't clear already.