Because

  1. You felt your self worth is attacked.
  2. You feel that you are not as valuable to him as you thought yourself to be.
  3. You have expectations with him. You feel that this kind of behavior hampers your chances of you two being together.
  4. You have low self worth and your confidence depends on his validation.
  5. You need him more than he needs you.

What could be possible reasons

  1. He is not a text person. Many people don’t like communicating too much on text. They treat text only as a means to set meetings.
  2. He might be playing some mind game to make you obsessive for him.
  3. He might not have felt to reply to trivial text. Your text might not have anything which needs replying.
  4. He might value you less.
  5. He might be really busy or lazy.
  6. It might have been too late when he saw your text. Some people don’t reply to texts when they lose context. For example ‘what are you doing’ or ‘good morning’ has no reply after two hours.

Thousand many other argument. Never judge a person by his texting habits. Always judge people based on how they treat you in person or may be phone.

https://hemantpandeyblog.com/2017/09/16/does-love-fade-over-time-and-why/