I've always wanted to discuss this!
There was a lot of controversy before regarding the use of squiggle sliders.
The idea behind them is that it slows the slider down while creating a visual cue, often to add emphasis to a part. As long as the squiggles were consistent and the slider moved at a relatively constant speed throughout, it behaved very much like a slider slowed down with an inheriting section (actually, with the added visual squiggles it was easier to read in a lot of maps).
The current issue here is not the use of squiggles, but the use of them to slow down the slider in the middle of it, not consistently like previously used in this same map.
The problem with speed changing sliders like this one is the potential trouble it gives to readability. A sudden slider speed change can really throw off the player, so it needs to be handled with care.
In this particular example, the slider is set up very specifically. It starts off normal speed, and changes speed on slider ticks. Because of its change of speed on slider ticks and the way the slider is positioned, it is actually quite feasible to discern where the slider is changing its speed (the slider ticks being directly on the places where the squiggle starts and stops). If needed, an example of this technique being used would be in the map With a Dance Number at 01:03:226.
I feel that the current rule we have now doesn't take into consideration the visual cues and slider tick indicators that mappers put into their sliders to ease readability. I'm really happy to discuss this issue here as it has been bugging me for a long while.
EDIT: to reply to post made while I was typing
those wrote:
As soon as you integrate "player skill" into your argument, it nullifies it entirely.
I don't fully agree with this. Wishy was stating that these are readable by some others, which means that the others were able to pick up on the cues presented by it.
I remember my first experience running into circles directly placed under slider ends. I was not paying attention to the approach circle reaching the end of the sliders and I missed it entirely. It wasn't the mapper's fault or unrankable, however, it was just me merely not picking up on a visual queue presented by the game and mapper.