Exactly. If one "expert" is developing only for himself he can allow himself not to bother writing a script "clearly" (i.e. failing the programs that perform so

Exactly. If one "expert" is developing only for himself he can allow himself not to bother writing a script "clearly" (i.e. failing the programs that perform source checks). But as soon as the script is something that should be potentially sooner or later maintained by anybody else than the original author (and in any successful project that's practically sure) the only right policy is to produce the source code that's obvious and passes the source checks. An "expert" would have no problem to in no time adjust his three-line code to fulfill all the expectations of ShellCheck. If it takes more than that, that only proves that the checks are actually beneficial and even more important than the "expert" tells to himself: it proves that writing that specific code "cleanly" is actually hard for everybody.