The mishnah on Gittin 90a lists two starting reasons that could be grounds for divorcing one's wife:
ובית הלל אומרים אפילו הקדיחה תבשילו שנאמר כי מצא בה ערות דבר ר' עקיבא אומר אפי' מצא אחרת נאה הימנה שנאמר (דברים כד, א) והיה אם לא תמצא חן בעיניו
[He may divorce his wife] even if she burned his dish, as it is stated: “Because he has found some unseemly matter in her” . Rabbi Akiva says: even if he found another woman who is prettier than her, as it is stated “And it comes to pass, if she finds no favor in his eyes” (Deuteronomy 24:1).
1) Aren't these 2 reasons- burning her husband's food, husband seeing someone prettier- ABSURDY shallow?
2) Doesn't divorcing for one of these reasons run counter to the EXACT reason why Chazal instituted a Ketubah? (Ketubot 11a- "So that she will not be inconsequential in his eyes, enabling him to easily divorce her")