Much like magic, the blood of the aristocracy also has its limitations. However these are not limitations confined to anti-magic Kingdoms such as Camelot, they are global, and Morgana Le Fay sometimes hates the fact that she was cursed with both.
The sorceress in her blood calls for freedom with such alacrity that it overrules all other needs (love, air, water). But Morgana was also raised as royalty, and deep down her conflicted heart knows she cannot be both.