Kneeling down to propose marriage to a lady or guy you’ve been dating or not dating is certainly NOT Islamic. It is a strange culture which should never ever find a way amongst Muslims for some reasons.

1. It is an imitation of non-Muslims. One who imitates the Kuffār is considered one of them. If a believer chooses something because it is the new practice not minding where it came from or whose culture it is, such a believer might end up following the ways of the unbelievers, becoming like them and ending like them
2. Kneeling down to propose usually follows some duration of dating. The duration is usually a time where all forms of iniquities would have been committed. Thus, the public plea for marriage is therefore a show-off and needless drama. It is baseless and uncivilized.
3. Kneeling down to propose marriage publicly is disgraceful and as evidence has shown, it sometimes come at the cost of public humiliation and avoidable pains or public embarrassment and emotional blackmail. None of those is gracious or fitting for a Muslim.
4. It is extravagant. With all the drama often attached to public marriage proposals, the cost and energy of doing it despite the possibility of Fitnah, public humiliation and all, it is true that it is extravagant and certainly, not a way for Muslims.
5. It is deceitful and embarrassing. In Islam, the union must be formed on the basis of shared values, not coercion or emotional blackmail. Hence, marriage proposal should occur through the guardian of the bride-to-be. That dispels the possibility of deceit and embarrassment.
6. A Muslim is one who submits fully to Allah and His Messenger and designs his/her ways according to the dictates of Allah and His Messenger. Going away from that and romancing with the ways of the unbelievers is disobedience to Allah and His Messenger SAW.

We ask Allah to grant us better understanding, ease our affairs, protect us from misguidance and unite us with Muslims in Jannah, not with Kuffār in Jahannam. Āmīn.