Reference to my previous experience, there are several reasons to leave work some of the reasons as good reasons and some of it are not.
in first the good reasons as following:
find better job and start own project.
seconds bad reasons make employees disappointed and quite as following:
1- Environment of the company
2- no promotion
3- high pressure in work and work for three handled by one.
4- no applications and no loyalty from the company.
if we concentrate on the bad reasons, we will found all this reasons created by company's policies. even the good reasons will disappear if the bad reasons not there in the company due to no one like to change his good situation to a risk one.

As mentioned by gingeranderson, there is a close connection between challenges and praises. People who work in projects which have the same monotonous work for the whole time will eventually be frustrated and might quit the job. That is one of the main reasons. the other reason is that proper appraisal for the work which is being done in the project. It is very important for the people to cheer the success of the project and appreciate the hard work which has been put in it. Once they have both the respect for the work which they do and the love also then the job becomes very appealing to the worker. If there is no respect received from the team or even the seniors then the interest fades out  and the person might want to leave the job.

Limited recognition and praise and exciting challenging work are connected in a way. In my opinion the number one reason why people leave is not feeling like they are learning anything new. After doing the same thing for two or three years, it gets boring and useless to an extent; yes it does become easier and you get used to the tasks but it feels like you are not going anywhere with your career at this point. It definitely gets harder when there is no recognition whatsoever to your efforts, especially from the people that you are closely working with. So you start questioning 'I don't know why I am still here anymore'. Of course there is always a money aspect related to leaving a job but if everything else is going smooth and you are comfortable where you are then money comes with time. The only solution to this issue is picking up new projects that are challenging, where your knowledge and skills can be applied and at the same time you add to your learnings and experience by going through new challenges in the field. Only then it would be worth it to stay and have your name on a new project that you would be able to refer to in the future to describe your experience.

It makes sense that exciting and challenging work is what keeps people motivated to continue working, especially when their work is their passion. But I can also see how this correlates with the #1 reason for why people leave work, which is not being recognized or praised for the work that they are doing. The overall motivator for working hard and striving to achieve personal goals and the goals of your company should not be receiving praise from others, but in some cases, no praise at all can be very detrimental to an employee's motivation and confidence. Although the need for outside praise and approval should not be necessary if you enjoy your work, being recognized for the work you are doing is what can keep you going sometimes and can also help prevent burnout.

So looking at this issue at face value, I would 100% agree with you here, they don't seem to correlate at all. If what motivates people to work is exciting/challenging work, then leaving a job because you aren't getting recognition for doing work that interest you seems a little strange to me. Especially since in the survey of what motivates people to work, to "Be recognized/valued and respected" was sixth on a list of eight. It, to me, is an example of how people are never satisfied. Personally, I like to say "I'm good at minding my business", meaning, while recognition is nice, it shouldn't be what you need to get out of bed and come into work. Everyone at your job is working, everyone comes in and does what they need to do. Not everything needs to be done for an award, in my opinion, things need to get done and that will happen one way or another. In today's day, everyone at the working level is somewhat expendable. At the end of the day, there will always be a worker who can do what you do without needing the praise/recognition to do it. I'm not saying that wanting recognition is bad but, like I said before, it shouldn't be the reason you don't want to go to work. Unfortunately, that's the way I look at it.

I believe people leave work because they are not happy in the company anymore. It could be for many reasons such as the employee might not have a healthy relationship with the manager, or they are not getting paid well enough. Another reason could be they are not challenged and their work becomes boring. Sometimes the commute plays a factor as well. If the employee is not satisfied with their work anymore, they won't have the motivation to continue. This could jeopardize the company because if people leave, they need to start recruiting more people and get them trained so they are going to be delayed in some projects.