We should read or understand Chapters 22, 23 and 24 of Uma Samhita of Shiva Purana completely to get proper meaning. In these 3 chapters, Vyasa asks Sanatkumara to explain things so that he can get Vairagya (detachment). Sanatkumara here explains things in such a way that Vyasa develops detachment.
From Chapter 22 of Uma Samhita,
विधि तात वदेदानीं जीवजन्मविधानत:।
तस्यापि वैराग्यार्थं मुनीश्वर॥१॥
Vyasa said, “O excellent sage, how does the living being remain in the
mother's womb in the process of birth. You kindly mention with
purpose of achievement of the vairagya or detachment.
शृणु व्यास समासेन शास्त्रसारमशेषतः।
Sanatkumara said, “O Vyasa, I shall now speak out in brief the essence
of all the Scriptures, which bestows detachment and removes the
Sanatkumara can explain how birth happens in simpler way but he chooses words demeaning physical body and sensual pleasures, so that it can develop Vairagya. You can read complete Chapter 22 to understand it in detail. Let me quote some verses said by Sanatakumara.
यथा गिरिवराक्रान्तः कश्चिद्दुःखेन तिष्ठति।
तथा जरायुणा देही दुःखं
As a person Surrounded by the mountains (slanting lands), feels
miserable, similarly the jiva having been surrounded by the membrane
in the womb, feels miserable.
पतितः सागरे तद्वद्दुःखमास्ते समाकुलः।
As a person feels disturbed with a fall in the ocean, similarly the
creature, during the period of pregnancy, having been drowned in the
water of the womb feels painful,
लोहकुम्भे यथा न्यस्त: पच्यते कचिदग्निना।
गर्भकुम्भे तथा क्षिप्तः
As a person is roasted in an iron vase with the fire, similarly the
creature placed in the vase like womb is heated with the gastric fire.
Here Sanatkumara explains painful side of rebirth so that Vyasa can develop detachment and thereby he can avoid rebirth.
From Chapter 23 of Uma Samhita,
शुक्रशोणितसंयोगाद्देहः संजायते यतः।
The body is considered to be impure, because it is formed of the semen
and blood and is filled with filth as well as urine.
यथान्तर्निष्ठया पूर्णः शुचिमान्न बहिर्घटः।
शोध्यमानो हि देहोऽयं
It is like a vase filled with filth and as such, though it outwardly
looks pure, but in reality it is impure. Similarly, the body though is
purified outwardly, but inwardly it is not so.
सम्प्राप्यातिपवित्राणि पञ्चगव्यं हवींषि च।
The extremely auspicious pancagavya as well as the havirdravyas also
get polluted with the mere touch of the body in a moment. What more
impurity could be these.
हे जनाः किन्न पश्यन्ति यन्निर्याति दिनेदिने।
पूतिस्तदाधारः कथं शुचिः॥६॥
O humans, do you not observe that the filth and urine, which daily
emerges from the body, (which are impure) then how could the body,
which is the source of the same could be pure?
But same chapter says the man whose mind is pure can make his body pure. You can see Sanatkumara is explaining things in such a way that Vyasa develops Vairagya.
Sanatakumara also says:
स्त्रीष्वध्यासितचित्तस्य ये पुंसः शुक्रबिन्दवः।
ते सुखाय न
मन्यन्ते स्वेदजा इव ते तथा॥५५॥
The drops of semen of a person who is lustful with his mind engaged in
women when dropped, they cannot make him comfortable like the drops of
कृमिभिस्तुद्यमानस्य कुष्टिनो वानरस्य च।
A leprous monkey, when it scratches itself having been afflicted with
worms, the same pleasure is derived by cohabiting with a women.
यादृशं मन्यते सौख्यं गण्डे पूतिविनिर्गमात्।
मन्तव्यं नाधिकं तासु विद्यते॥५७॥
The pleasure one derives from the company of a woman, is equal to the
pleasure derived from a boil by removing the puss. There is nothing
more to it.
These strong words are aimed to develop Vairagya.
In Chapter 24, Vyasa asks story of Apsara Panchachuda and Narada (which seems to be famous story among Sanyasa to develop Vairagya). All those quotations about women are opinions of Apsara and whole purpose of recounting this story is to develop Vairagya. This is what Sanatkumara says at end:
इति श्रुत्वा वचस्तस्या नारदस्तुष्टमानसः॥
तथ्यं मत्वा ततस्तद्वै
विरक्तोऽभूद्धि तासु च॥३६॥
Sanatkumara said, "Listening to the Words of the nymph, and taking
them to be true, Narada felt detached.
इत्युक्तः स्त्रीस्वभावस्ते पञ्चचूडोक्त आदरात्।
वैराग्यकारणं व्यास किमन्यच्छ्रोतुमर्हसि॥३७॥
O Vyasa, I have narrated about the nature of the woman, as was
explained by the apsara Pañcactida, which is the cause of my getting detached. Now what else do you intend to listen from me.
Sanatkumara says this story helped him in getting Vairagya.
Does that mean Sanatakumara really hates Human body as he said it is
No. In chapter 20 of same Umasamhita, Sanatakumara praises human body as vehicle to Moskha and says it is even difficult for Devas to attain Humanbody.
मानुष्यं च समासाद्य स्वर्गमोक्षप्रसाधनम्।
नाचरत्यात्मनः श्रेयः स
मृतः शोचते चिरम्॥३०॥
The human body is the means for achieving of the heaven and moksa and
even after achieving the same, he does not do good to himself. After
death he keeps on thinking for a long time.
देवासुराणां सर्वेषां मानुष्यं चातिदुर्लभम्।
तत्सम्प्राप्य तथा कुर्यान्न
It is difficult for even the gods and the demons to achieve the human
body. Therefore after achieving the human body, one should act in a
way that he has not to face the agonies of the hell.
Uma Samhita itself praises Divine Mother or Shakti from Chapter 46. As explained in other answer, Chapter 4 of Vyayaviya Samhita (Uttara Bhaga) praises woman as Divine Mother.
शङ्करः पुरुषाः सर्वे स्त्रियः सर्वा महेश्वरी।
सर्वे स्त्रीपुरुषास्तस्मात्तयोरेव विभूतयः॥५४॥
All the men represent
Shankara, while their spouses represent Shivaa (Maheswari). Therefore
all the men and women represent the grace of both of them.
So, Shiva Purana doesn't demean women.