In addition to Rachet Freak answer I'll add that helicopter engines are subject to much dirtier air. Aircraft operate from runways which are relatively clean. Due to their speed, most dust and debris that is kicked up is behind the engine inlet so it is not sucked in.
Helicopters hover and land vertically and therefore their engines ingest air contaminated with kicked up dust. Especially when operating outside paved surfaces this results in considerable pollution. A filter is much more useful here.
Dust does damage the blades but the effect is like sand blasting; it takes some time to cause structural damage. The turbine engines of airliners can take some dust (by design) but also get extensive maintenance regularly. And if they do get caught in a dust storm they should get out ASAP and get the engines inspected.
The biggest danger dust-wise is volcanic ash as that will adhere to the turbine blades behind the combustion chamber and potentially shut the engine down due to compressor stall. This happened with British Airways Flight 9 where all 4 engines failed. This is why a volcano can shut down Europe airspace.