Developers have reasons to suspend projects that they have run for reasons of the market situation and the lack of interest from investors in new projects, failure to achieve the soft caps they are targeting can temporarily stop the project until the developers get the funds they are targeting to develop projects with minimal funds.
Some developers have successful token sale, even hit hardcap but along the line they halt everything about their project. In this case, it's obvious the initial purpose of the project is "money grab" only, without intentions to develop the project. Some will have mind blowing Whitepaper with awesome milestones to be achieved on roadmap, but at the end won't achieve anything. However, some projects do halt due to mismanagement of funds or insufficient funds to continue with project development.