That's just the way Captivate has always worked and it still works that way now.
If you like the idea better, you could set up an Advanced Action that pauses the slide a few seconds in. (There's a new Delay action that can be used on Standard and Conditional Actions.) But you'd have to add that Action to the On Slide Enter event of every slide.
Personally I don't have any problem using an interactive object to pause the slide. It means I can choose whether I want the slide to pause or not.
I can choose whether I want the slide to pause or not by clicking a check box in Storyline Or do it globally for all slides with a single click.
I don't like tedious repetetive tasks. Not that Storyline doesn't have plenty of those (ahem no automatic slide numbering).
Do a Google Search on "How do I make Adobe Captivate NOT auto advance?" The number of returns should offer a clue that this is a feature people have requested for YEARS.
The people logging those posts about not knowing how to stop Captivate from advancing automatically are usually newbie users that haven't had any training or read the HELP files yet. Some like you, came to Captivate from Storyline and expected it to work the same way. It doesn't.
If you prefer Storyline, by all means use it. I've used both and I prefer the way Captivate works. I found it annoying that Storyline had no objects which allowed you to easily pause the timeline. So this 'issue' seems to be just a personal preference.
If enough people request a particular enhancement Adobe listens. Personally, if I were on the development team, I wouldn't see what you're requesting here as a particularly HUGE need.
Please leave ad hominem attacks out of this discussion. Calling someone a "newbie" and insulting their capabilities when they are commenting on what they perceive as a missing feature is ignorant.
By the way, you don't need objects to pause the timeline in Storyline, you can do it with triggers. Newbie!
It doesn't have to be repetitive: insert one shape button on the main master slide and set it to pause, it will pause at the end of each slide whatever its duration. Triggers can do the same in SL? No repetitive tasks? I'm bit kidding
The main difference is you don't even need to set a trigger in Storyline.
Look, I know you guys are heavily invested in using Captivate, that's fine. I also don't care if you use PC or Mac. Or drink Pepsi or Coke. I just think this would be a good feature to have.
As to putting the object on the Master Slide, doesn't the time timeline pause as soon as it encounters the shape? So if you have slides of different time lengths that wouldn't work, correct?
That works perfectly, because items on a master slide have no timing, no ID. The team arranged it so that if you set a shape button on a master slide to pause, it will always pause at the end of each slide, whatever its duration. That is what I wrote the first time, but of course, I'm not a native English speaker, English is only my third language