The core of the problem with this entire topic is that macOS has no centralized uninstall process. The uninstall procedure is described in the documentation, also available through the Help menu in all versions of Malwarebytes' Mac software, as well as in the following articles on our support site: (That uninstaller was shipped with the installer for those versions of the software, but is still available for download for those who might have thrown it away.) If you have Malwarebytes for Mac 3.0 through 3.0.3, download and run the uninstaller for those versions of the software from here: If you have deleted the application without properly uninstalling, download and reinstall it, so that you can open it and use the Uninstall option. If you have Malwarebytes for Mac 3.1 or later, open the Malwarebytes application and choose the Uninstall option in the Help menu.
If you have Malwarebytes Anti-Malware for Mac 1.1 through 1.3.1, open the Malwarebytes Anti-Malware application and choose the Uninstall option in the Help menu. There's a lot of needless bickering going on here, so let me clarify what the right way to remove the software is.