Every order would benefit to have the best & brightest working in the various fields of inquiry and enterprise.
If, say, a social order prohibits social advancement to non-believers and admits only avowedly religious persons, then it will miss out on the talents of atheists and agnostics. To be sure, some may lie and pretend to be religious. But anyone who remains true to his convictions will summarily be denied entry to competition. The problem will be compounded if the many intelligent people happen to be non-believers. Then, all that talent will never see the light of day. Consider all the smart people who were sent to toil on farms during the radical Maoist era that insisted on ideological purity.
Granted, if most intelligent people were religious and most dummies atheist/agnostic, then the impact of suppressing non-believers will be far less deleterious. When even most intelligent Europeans believed in God in the pre-modern period, it wouldn't have made much of a difference if non-believers were banned from institutions of higher learning. But as scientific discoveries began to cast serious doubt on Church teachings, increasing numbers of smart Europeans tended toward disbelief. Therefore, restricting science and math only to the religiously-inclined would have held back in advancements in those fields.
In the several decades following the end of World War II, the impact of ideological taboos had a minimal negative impact. The reasons were twofold. Most intelligent people sincerely believed that Race was more a social construct than a biological fact. So, even if people deemed 'racist' were banned from hiring and promotion, it didn't affect the hiring of the best and brightest. Also, the definition of 'racist' wasn't as broad as it eventually came to be. By today's PC standards, even most liberals of the not-too-distant past would be deemed 'racist', as well as 'homophobic', 'antisemitic', and 'xenophobic', not to mention 'sexist' and 'misogynous'. Back in the 50s and 60s, a 'racist' was someone in the Klan or someone who explicitly resorted to racial slurs against minorities in the West.
And most people deemed outright 'racists' in the past were indeed rather low-grade in terms of ability, achievement,and moral character. So, banning such people hardly affected the talent pool of America. It'd be like banning cripples from sports. The best would still play. It was not like banning Jews in National Socialist Germany that immediately impacted the quality of the sciences, especially in physics and mathematics. Or like the suppression of Jews in the Soviet Union. Though the Soviet Union was never explicitly anti-Jewish, its harsh stance against Zionism led to the blacklisting of many Jews suspected of greater loyalty to the Tribe & Israel(and by extension the US) than to the USSR. Because of the higher intelligence of Ashkenazi Jews, this led decrease in talent pool in key Soviet institutions.
Anyway, PC might finally begin to impact the talent pool in the West. For one thing, the New Right in both the US and EU is not made up of low-grade morons who made up the bulk of KKK, Neo-Nazis, skinheads, or far-right cranks. Many people in the New Right are pretty bright, and their views are actually more grounded in facts of biology, laws of history, and needs of morality. So, the blacklisting of the Right in the 21st century will not just deny hiring and promotion to far-right dummies but to a growing number of men and women of talent.
Even more troubling is the way in which PC has rendered promiscuous the meanings of 'racism', 'antisemitism', 'homophobia', and etc. In the current year, just about anything can be construed as 'racist' depending on the feelings of the aggrieved or 'triggered'. So, even if you did nothing, you could end up like Joseph K. of THE TRIAL, accused of crimes you have no idea you committed. Worse, even 'hate hoaxes' perpetrated by blacks, Jews, and homosexuals are less likely to be condemned than showcased as 'teachable moments', indeed even after the hoax has been exposed.
'Racism' now means the failure to flatter blacks and their egotistical delusions 24/7. 'Antisemitism' now means the mere act of noticing Jewish Power and/or being critical of it. 'Homophobia', a bogus term for a non-existent phenomenon, means not being properly deferential to vain homos and their narcissism. As if that isn't absurd enough, there are also panics about 'transphobia', something one could be accused of if he believes a man is still a man despite his insistence that he is now a 'woman'.
As more and more intelligent people become aware of the reality of race, key differences between the sexes, degeneracy of the homo-tranny agenda, and/or the problems of various non-Western Cultures due to mass-'immigration'/colonization, AND FURTHERMORE, as PC Taboo casts a wider net as to which attitudes & actions constitute Thought Crimes, it is inevitable that the West will increasingly suppress real talent and integrity(a necessary quality for courage and honesty to speak the truth) in the Talent Pool, and as a result, meritocracy will suffer in many fields of science, letters, enterprise, and arts & culture.
Banning 'hate' in the past used to mean denying voice and choice to low-grade dummies. Now, banning 'hate' means the suppression of any able, honest, and courageous voice that is hated by the globalist elites, most of whom are contemptuous Jewish supremacists and their craven shabbos goy cuck-whites.
To work for any 'progressive' outfit, one must not only denounce the KKK & Neo-Nazis but revere homos & trannies and keep mum about the overwhelming reality of Jewish Power. Also, one must make believe that black problems today are still on par with race problems of the Jim Crow Era. According to PC, any white person who boycotts the NFL is a 'racist'. That's a lot of people who could very well end up on the PC blacklist.
The future will be interesting as Liberalism has gone from expanding meritocratic freedoms to more kinds of people to limiting meritocratic opportunity only to those who adhere to Politically Correct dogma.