There are many reasons that a user can uninstall an app. Including due to some basic generic reasons, performance issues or trust issues as indicated in the below infographic.

Basic Generic Reasons Users Uninstall Apps

An app user could determine that your app is no longer useful to them, just doesn’t meet their expectations or it simply is no longer relevant.
Some may find that the app is weak and lacks performance while others feel that they are more apps available in the marketplace for them to choose from. Whatever the reason, there are several areas that developers need to be mindful to to reduce the occurrence of users uninstalling their apps.

Then there are the cases where users feel forced to make the updates which can be both inconvenient and uncomfortable.

Performance-Based Reasons

Some users may also uninstall apps due to poor performance, such as a very high CPU power usage or because it drains their batteries a lot faster when the app is the used.

Some apps take much too long to load which causes users to become impatient, whereby they basically remove the app from their mobile device altogether. Apps that catch too much data is another form of inconvenience experience by app users that could cause them to uninstall the app as well.

Trust Issues

Many app users also uninstall apps because of trust issues. For example, there could be an indication that the app has a malware or that the app only works well on faster networks. Additionally, some users feel that the app sends far too many invites to the user’s friends without their permission or knowledge. This can cause app usage to feel uncomfortable and creates major distrust issues. When the app requires too many permission on social media networks, users tend to shy away from the use of the app for that reason as well. And lastly, whenever users
have problems or inquiries but never received a response from developers they will experience issues with trust as well. This results in the user ultimately uninstalling the app as well.

Source: Dot Com Infoway