Why do Buddhists believe there is no creator? Why do Buddhists believe there is no creator?

Do Buddhists in general also believe there is no supreme being, or do they settle on that there is no intervening supreme being?

Are these the Buddha's thoughts or a deductive conclusion from some type of logical reasoning? If they are mainly the Buddha's, how come they are generally accepted - as far as I understand it, he encouraged everyone to not take his word for anything, but instead seek the truth for themselves?

As you understand I'm a total Buddhist noob, please correct me where I'm wrong and clarify where needed!
For most people God is a dualistic concept. Meaning, for a typical person the unspoken assumption is: "I am here and God is over there". So when I think about God, when I speak to God -- I inevitably imagine some power outside of myself. It is in this power that I place hope for good life and for salvation; it is this power that I blame for unfairness etc. According to Chogyam Trungpa Rinpoche, by attributing to God the power to save us or to send difficulties etc. we alienate ourselves from our own power.

Instead, in Buddhism our liberation is always in our hands. As Trungpa Rinpoche said, no one is going to descent in the golden chariot to take care of you. As long as you keep looking up to some higher power, how can you be the master of your life?

Two of my teachers emphasized such "master consciousness". My Zen Master said: "People say, 'God bless you', but Enlightenment is when you bless God". My last teacher said: "Utilize God". Both remind us to take ownership of our lives.

Not that [Mahayana] Buddhists deny the Absolute. What they deny is existence of independent "I" in the absolute sense. "I" is a label, a nominal designation that only exists relatively to other things. However, because the relative is subsumed in the absolute - not opposed to it - we can't deny existence of the relative either. This (here simplified) position is known as the unity of two truths. From this non-dualistic perspective, my power and the power of Absolute is the same power, my will and the will of Absolute is the same will, and my spontaneity and the spontaneity of Absolute is the same spontaneity. Using it and being used by it refers to the same activity. As Jesus said, "I and the Father are one." So, like I said in this answer, "Could we go as far as to say that Buddhist path culminates in the first-hand knowledge ... of God?"