The phrase "rightfully concerned" is correct and usable in written English.
It is commonly used to describe an understandable worry or fear, so it can be used in a variety of contexts. For example, "The parents were rightfully concerned about their children's safety in the storm."
Society is rightfully concerned with the neglect of the elderly.
And M.I.T.'s officials were rightfully concerned, the government argued, by the threat they faced.
"Issuers are rightfully concerned about the integrity of the interest rate setting process".
"But the Taliban acted unilaterally, and now they're rightfully concerned that no assistance is forthcoming".
Stevan Ridley (NE) vs. Miami — Most Ridley owners were rightfully concerned about his Week 7 matchup with the Jets' stout run defense.
"I think consumers would be rightfully concerned about the safety of the driver position that only got a '2' in this frontal crash test," he said.
The lines between convenience and privacy continue to be blurred across so many emerging disruptive technologies — and frankly, the idea of regulating airspace that is so (physically) close to people is something that is rightfully concerning, because people don't want drones dropping on their heads or looking in their windows.
Even if most of the ongoing chatter about representation in popular culture rightfully concerns the second-tier treatment of women and people of color, Besson's objective speaks to the evolution of male vulnerability on the big screen.
There is rightfully concern about the potential for data and technology to further inequality within cities.
"Given the lack of serious competition in the near future, and the vast potential for sequencing that is already starting to appear, the board should rightfully be concerned about unnecessarily truncating value by selling the company too soon, and at too low a price," I.S.S. writes.
But other shows, like Nau Rauch's exhibition of the German artist's incoherent, cartoon paintings rightfully leave viewers concerned about where the museum's money is and isn't going.
