Yes and no. My grandfather was born in Germany. In that 1920s-1940s culture, Christians had largely already abdicated the political arena (Luther's two kingdoms theory). At some point, that culture got to its point of no return, and that any true salt and light activity by Christians resulted in the likes of what happened to Bonhoeffer or Wallenberg (Hungary).
That's where the true Greek word of martyr comes into play--where the only way to flesh out that word in a godly way is to lose your life for your witness.
Since many who call the name of Christ will avoid losing their lives, then, yes, their ability to be salt and light is going to be compromised by the surrounding culture.
Beyond those kinds of cultures, being salt and light may not be dependant upon the surrounding culture, but will be largely influenced by it. If you have water pollution but don't really care about the political reality of clean water laws, then don't complain...the polluters have thereby won the day over whatever salt & light Christians could have been as applied to drinking water.
Bottom line: Christians need to go back and read through all the corporate guilt and corporate responsibility passages oultined in Scripture...Luke 10:12-15; Dt. 21:1-8; Prov. 24:11-12; Is. 1:9-17...all the identifical repentance passages of the prophets--those who identified with the sins of their nation even though they personally may have been innocent of them.
I'm puzzled. If, in a hostile culture, they "avoid" losing their lives for their witness, then they are not salt nor light by their own choice. Nor does He confess them before His father, by the way.
Jesus seems to assume, multiple times in fact, that Christians will be salt and light in a culture that hates them and will kill them.
So...is it supposed to work differently?