Why is it when BL with big pecs is good and great but when a FL is involved in a straight manhwa with big breasts its un-proportionate and weird?

Im an avid reader of both but alot of 18+ BLS will have one guy with big tits and everyone in the comments is thirsting, however if its a straight 18+ manhwa and the FL has big breasts its all of a sudden un proportionate and weird and they need to drop the manhwa because they cant stand it? This has to be internalized mysoginy idk.