That tired phrase is the funeral lament of individual freedom and privacy rights. It is also the swan song of tyrants who want to run roughshod over their subjects and create a culture of fear, compliance, and nanny statism.
IN a free, fair and democratic society, the correct statement is "It is precisely because you have done nothing wrong, that law enforcement has no reasonable grounds to search".
Searches are not permitted by default. They have to be justified based on reasonable submission of wrongdoing. When consenting to searches because you have done nothing wrong, you have nothing to gain, and everything to lose.
Getting flagged for lawful activity is a big deal, especially when the government has absolutely no data to substantiate what should or shouldn't constitute a flag.