There could be several reasons why the guy you were dating didn't reply to your message or ask for the reason after you told him you didn't want to meet again:
Shock or surprise: He might have been taken aback by your message and needed some time to process it before responding.
Respect for your decision: He may have chosen not to push for an explanation because he wants to respect your feelings and boundaries. He might feel that if you don't want to continue the relationship, it's important to honor your decision without pressuring you for a reason.
Hurt or upset: It's possible that he was hurt by your decision, and as a result, he didn't respond immediately.
Lack of interest: Unfortunately, it's also possible that he wasn't as emotionally invested in the relationship as you were, so he didn't feel the need to seek an explanation for your decision.
Uncertain how to respond: Sometimes, people are unsure about the appropriate response to such messages, especially if they're not skilled in handling emotional situations.
Fear of confrontation: He might be avoiding a potentially difficult or awkward conversation about the end of the relationship.
Busy or preoccupied: Life can get busy, and he might have had other priorities that prevented him from responding right away.
It's essential to remember that people respond differently to various situations, and not receiving an immediate response or an inquiry about the reason doesn't necessarily mean he doesn't care or wasn't affected by your message. If you need closure or have unresolved feelings, consider reaching out to him again and expressing your desire to talk things through. However, if he continues to not respond or shows disinterest, it's best to focus on healing and moving forward with your life.