Same here. It made me realise that un- is the wrong prefix for what we mean by uninstall. It should probably be de-, as in "I deinstalled the program" or "This app is deinstallable".
It’s not the wrong prefix. It’s the same ‘un’ you get in e.g. ‘unlock’ or ‘untie’. The ambiguity of words like ‘unlockable’ or ‘untieable’ is a standard exercise for morphological tree drawing in Linguistics 101 ([un [lock able]] or [[un lock] able]). The existence of structural ambiguities in words isn’t really any more disturbing or problematic than the existence of structural ambiguities in sentences (e.g. ‘John saw the man with a telescope’).
(Technically, ‘unlockable’, ‘uninstallable’ etc. don’t exemplify pure structural ambiguities because the ‘un’ prefix is used in two different senses, but the two meanings do have different structures.)
