No, really, he does:
Richard E Grant believes that straight actors should not play gay characters.
The Oscar-nominated star is opposed to what he sees as heterosexual performers taking the parts of their homosexual colleagues.
The portion of the acting profession that professes gayness is rather higher than that of the general population. Rather higher than that prevailing among the parts being played. Thus to insist upon casting by sexuality is to deny many gay actors work.
For this will work both ways, right? If the cis and hetero cannot take parts that are not cis and or hetero then those not cis or hetero cannot take parts which are?