Why does hinduism has so many gods? With so many gods, how can one focus, are they not distracted?
A brief classification of the expansion of the Supreme:
- There is one Supreme Person who is the source of everything and Lord Krishna declares Himself as that Supreme Person in the Bhagavad Gita (Example: 10.2 10.8 7.7). This is also mentioned in the Srimad Bhagavatam as well. His own expansions are all Vishnutattva and considered non-different from Him. So when we speak of God with upper 'G' it is the Vishnutattva. As far as why He has so many Vishnutattva forms He does this for His own pleasure to interact with His devotees in various rasas (mellows). Lord Siva is considered a special expansion (like curd from milk) who is superior to Jivas but not the full manifestation of the Supreme.
- Another category is Jiva tattvas, who are seperated expansions and demigods(what you call as gods) generally fall into this category. They are there to take care of various universal affairs. Some times the Supreme Lord himself accepts the postion of the devas like Brahma when there is no suitable jiva to occupy the post.
In regards to worshiping various devis and devatas Lord Krishna clearly says that this is done by people whose intelligence is stolen (hrta jnana). They do so because they have material desires. These devotees of various demigods go to the demigods' planets but those who worship the Supreme Lord Krishna goes to His eternal abode. Even if people go to Brahma-loka, unless they receive the mercy of the Supreme Lord to go to impersonal Brahman or Vaikhunta, they have to come back to the material world.
Some relevant citations from here
BG 7.20: Those whose intelligence has been stolen by material desires surrender unto demigods and follow the particular rules and regulations of worship according to their own natures.
BG 7.24 Men of small intelligence worship the demigods, and their fruits are limited and temporary. Those who worship the demigods go to the planets of the demigods, but My devotees ultimately reach My supreme planet.
BG 8.16: From the highest planet in the material world down to the lowest, all are places of misery wherein repeated birth and death take place. But one who attains to My abode, O son of Kuntī, never takes birth again.
So it is clear that Lord Krishna is recommending us to worship Him only. He clearly mentions this in several places and also asks us to give up other methods and just surrender unto Him.
BG 18.66: Abandon all varieties of religion and just surrender unto Me. I shall deliver you from all sinful reactions. Do not fear.
So when people do not accept these instructions and have their own motivations they will not surrender to Krishna but worship various demigods. As far as Bhagavad Gita (teachings of the Supreme) and Srimad Bhagavatam (descriptions about the Supreme) is concerned they are as clear as the sun shine. Today is the auspicious day of Gita Jayanti and here is a relevant verse of Gita Mahatmya that glorifies Gita and Krishna:
ekam sastram devaki-putra-gitam eko devo devaki-putra eva eko mantras tasya namani yani karmapy ekam tasya devasya seva (Gita Mahatmya 7)
Srila Prabhupada explaining the above verse states:
In this present day, people are very much eager to have one scripture, one God, one religion and one occupation. Therefore, ekam sastram devaki-putra-gitam: let there be one scripture only, one common scripture for the whole world – Bhagavad-gita. Eko devo devaki-putra eva: let there be one God for the whole world – Sri Krsna. Eko mantras tasya namani: and one hymn, one mantra, one prayer – the chanting of His name: Hare Krsna, Hare Krsna, Krsna Krsna, Hare Hare/ Hare Rama, Hare Rama, Rama Rama, Hare Hare. Karmapy ekam tasya devasya seva: and let there be one work only – the service of the Supreme Personality of Godhead.
You ask 'With so many gods, how can one focus, are they not distracted?' Those who get lost in Vedas are distracted as you say and get entangled in fruitive work forgetting the real goal of life. Hence you see in Srimad Bhagavatam that Vyasa was not happy even after dividing Vedas and writing Mahabharat as well. Narada Muni while telling the reason says:
SB 1.5.8 — Sri Narada said: You have not actually broadcast the sublime and spotless glories of the Personality of Godhead. That philosophy which does not satisfy the transcendental senses of the Lord is considered worthless.
SB 2.3.10 — A person who has broader intelligence, whether he be full of all material desire, without any material desire, or desiring liberation, must by all means worship the supreme whole, the Personality of Godhead.
So those who take the Gita and Bhagavatam as it is are not distracted.