... there is no reason why Tixati can't just write these files to the same location that the Tixati 'exe' is stored in ...
In Linux, if you want a singleton instance, you need a lock file, and you need a domain-socket file to do inter-proc comm to launch files from the shell. These have to be in a common place, independent of the location of the launched binary. Period.
I wouldn't expect someone without experience developing Linux apps to understand the reasons, but it's pretty standard knowledge that this absolutely is the way things have to be done. The devs clearly know what they're doing in this area, it's not easy to get right.
... files still exist on the hard-drive, deleted or not - it's just that you can't ordinarily see them if they are deleted ...
Expecting any app to do forensic hard-drive cleanup/scrubbing after every file deletion is getting even more ridiculous. Should all traces of the app be scrubbed from the shell too? The environment keeps MRU lists, command history, system logs, and other evidence, better take care of all that too while we're at it...