"justifiably considered" is a perfectly valid phrase to use in written English.
You can use it whenever you want to indicate that something is being considered in a reasonable or justified way. For example: His position on the issue could be justifiably considered as outdated.
Sokolow (South) played the diagramed deal from the pair event correctly and justifiably considered herself unlucky.
For his technique, ambition and reach, 40-year-old Italian director Paolo Sorrentino is justifiably considered an emerging master of modern cinema, crucially nurtured here at Cannes.
Violence, threats of violence, destruction of property and harassment are justifiably considered criminal acts no matter how worthy the cause for which they are perpetrated.
Now for the multiple caveats: Nadal, winner of six French Opens, is justifiably considered by many the greatest clay-court player in history.
Directly or indirectly, Florida's tropical and subtropical climate affects nearly every aspect of the local economy, and it can be quite justifiably considered the state's chief resource.
Lincoln waited almost a month, until June 12, to respond in a letter that is justifiably considered one of his most masterful public communications.
They can already, and justifiably, consider themselves potential winners.
One long-time regular I run into there is Luis-Manuel Garcia, an ethnomusicologist and writer who has a focus on the social dynamics of Berlin's techno scene and spends so much time in Berghain he justifiably considers Panorama Bar an extension of his living room.
If the issue is one on which there could be more than one truthful perspective — for example, the sufficient conditions for spending eternity in God's presence — to be a pluralist is to claim that the religious perspectives of more than one basic theistic system or variant thereof can justifiably be considered equally close to the truth (Marbaniang 2010).
For example, systems that run nuclear power plants or the electric grid should justifiably be considered more regulable, while your local web hosting service should not be.
We conclude therefore that homeopathy can justifiably be considered a complex intervention.
