Un-inviting means not attractive, unwelcoming and dull. Some suitable antonyms for un-inviting could be inviting, friendly, welcoming or alluring. An inviting environment makes people feel warm and comfortable, while friendly people create pleasant vibes. Such an atmosphere creates a sense of hospitality that makes people want to stay and engage for a longer period of time. An uninviting environment or people may result in guests feeling unwelcome or uncomfortable. Therefore, having a welcoming and charming atmosphere or people can increase the motivation for individuals to interact and enjoy their surroundings, leading to a more positive atmosphere overall.