Creators are praised extensively, be it in any sphere - such as technology, fashion, education, and what not. If it is so for these disciplines that humans walk through every day, what should be the level of devotion for the person who created the entire universe and the place where we live in?
When it has a religious dimension, people are definitely into it wholeheartedly. On the contrary, in Hinduism, Brahma the creator, is not praised, worshipped or even talked about much like Vishnu and Shiva, who together constitute the Trinity of Hinduism. There are not many temples in His name too. Have you ever known why it is so?
Brahma is also the originator of the four Vedas, which are dear to Hinduism. All of His creations are remembered but not Him. There is definitely a reason behind such an approach to Brahma and the mythological side of it is discussed here. These legends will tell you why.
Along with the creation of the universe, Brahma also created Shatrupa, a daughter from His own seminal fluid. She is also referred to as Goddess Saraswati. She was so beautiful that Brahma forgot His purpose of being and started tracking her wherever she went.
Shatrupa sensed that His desires were not right, fled from Him and even fell from the sky; but Brahma sprouted four other heads to keep an eye on her. He had only one head when creating the universe. This is how Brahma became five-headed. Some even believe that the fifth head was chopped off by Lord Shiva for this unholy behaviour of Brahma's.
Shatrupa was definitely not for this and she kept changing forms to escape from Brahma. He is actually her father or creator. Raged and feeling disgusted with this act, she cursed Brahma that He will not be worshipped by anyone on earth.
Once, there arose a quarrel between Brahma and Vishnu. Both of them were on the quest of finding out who was greater. They asked Lord Shiva to intervene in order to sort out the issue. He gave them a task. Whoever saw the top of Shiva's head first would be considered greater. For the task, Shiva took the form of a linga, which extended beyond the universe. Linga is the phallic symbol of Lord Shiva. Brahma and Vishnu understood that it was not going to be easy.
Lord Vishnu was clever. He performed prayers to Shiva and fell at His feet finally. Lord Shiva bowed down to lift him up. This way, Vishnu succeeded in finishing the task. On the other hand, Brahma resorted to tell a lie. He came across the Ketaki flower while on the quest.
He convinced the flower to testify that he had seen the top of Shiva's head. The flower agreed and told so to Lord Shiva. Shiva, on hearing the lie, cursed both the flower and Brahma. The curse was that Lord Brahma will not be worshipped by anyone, anymore, and that the flower will not be used in any of the religious rituals.
These are the mythological reasons for which Brahma is not worshipped in Hinduism, even though he is the creator of all. Another logical reason people say is that the work of Brahma is done once the creation is over. It is considered as the past.
Vishnu is the preserver and Shiva is the destructor, both of whom represent the present and future, respectively. People do not care for the past and only bother about the present and future. This perspective of thinking makes Brahma neglected.