Being the creator of the universe, Lord Brahma is considered one of the most powerful Gods with four heads. Despite such prominence he is not worshipped by the Hindu community and own just one temple in Pushkar.
Here's the reason :-
Once there occurred a dispute between Lord Brahma and Lord Vishnu on superiority. They chose Lord Shiva to take the decision. Lord Shiva decided to take the form of lingam and asked both of them to find the end of Lingam. Both of them agreed and got into their work.
After sometime they realised that there is no end to lingam. Vishnu came to the conclusion that Shiva is the greatest. But Brahma on the other hand tried to trick Shiva. He requested a Ketaki flower to testify before shiva that he had reached the end of the lingam.
The idea failed and Lord Shiva got furious and cursed Lord Brahma that he won't be worshipped by anyone. He also cursed Ketaki flower that it won't be used in any ritual.