I feel like unleashing all my wrath on to whoever utter this foolishness not because I'm a worshiper of Lord Shiva but the philosophies of ISKCON are blasphemous and are distorting the whole meaning of Hinduism.
Everyone with a little common sense and familiar with Hinduism knows the hierarchy of Gods in it. Basically, there were three main Gods. Brahma- the God of creation, Vishnu- the God of Protection and Shiva- the God of Destruction. Every single story of creation revolves around these three Gods. Either Brahma created the universe or Vishnu did or Shiva as well. Vaishnavists believe Vishnu is the Ultimate God and he was the source of creation while Shaivists believe Shiva as the most powerful one. But none of these theories in Puranas introduces Sri Krishna at the time of creation. Krishna only appear in Hinduism in Dwapara Yuga as an incarnation of Lord Vishnu. However, according to ISKCON, Krishna existed since the beginning and Vishnu is just an avatar of him. There are four Vedas, twenty Puranas and hundreds of Upanishads in Hinduism. Not one of them support the theories ISKCON proposes.
In recorded history, the very first God to appear in Hinduism is none other than Lord Shiva. Pashupati, the primitive form of Lord Shiva can be found in the Indus Valley Civilization around 3500 BC while Krishna emerged around 500 BC. People worshiped him as one of the ten Avatars of Lord Vishnu, not as the Supreme Godhead.
That is just plain history recorded by the archeologists. In the history according to the Puranas and Epics(which I personally believe as I got enough evidences to do so), we can find the personalities/incarnations of Lord Vishnu living on the face of the earth throughout. Vaman, Parasuram, Ram etc. Even the existence of Lord Krishna can be proved as the ruins of the sunken city of Dwarka is been found deep below the Arabian Sea. Shiva never appeared in just one point of time or event or in a particular yuga. Earth witnessed his presence more than once since the dawn of time. Why? Because Lord Shiva is above the yugas or time. Yugas are timescale of our world and Lord Shiva is beyond that. Check out- http://www.sivapurana.blogspot.in/2012/05/questions.html
The International Society for Krishna Consciousness has done a great job in taking the Indian Culture to the rest of the world. A lot of people all around the globe felt the divine call by the touch of Holy Bhagavat Gita. Unfortunately, on their process, ISKCON twisted, altered and distorted Hinduism. They have actually Chritianified Sanatana Dharma. It was formed by Acharya Bhaktivedanta Swami in 1966. Just a half a century old. This holy religious organization turned into a cult and tampered with the philosphies which are some 3000 years old.
What had lead to the misunderstanding that Lord Krishna as the Ultimate God? In Bhagavat Gita, Krishna says such things to Arjuna more than once. Its worth being followed but not literally. You see, Arjuna realizes that Krishna is not just an ordinary human being but is an incarnation of Lord Vishnu. In that sense, whatever Krishna says, its on behalf of Vishnu. Does that make Vishnu the Supreme one? No, Hinduism teaches All Gods Are ONE concept. Vishnu is the manifestation of Parabrahma. The one without a personal form. The energy which balances the world. The energy in you and me and all living and non-living things in the world.
If you still have confusion understanding, consider this illustration. Artificial Intelligence(AI) of your computer. Isn't it a single entity? Yes, the one which programs the whole machine. You're playing a game in it, suppose..FIFA13. The user(you) is playing against a team of 11 players. They are distinct 11 players but still they all are single AI. They all move in different directions, some tackling you, some guarding the goal post yet, they are one- the Artificial Intelligence. One of the player, lets give him a name, player-X scores a goal. Lets congratulate him- but wait...its the AI who is behind player-X's strength. Player-X dances, is it his skill? Yes...but its AI too. All other players in the opposite team is AI. Maybe, a player in your team scores a goal. Yes, its due to the player's skills but its yours as well. You should be appreciated for the goal.
So, Lord Krishna was right saying he is the supreme one. But he didn't mean literally, its the Nirakara Rupa Parabrahma who is the Ultimate God. The one without shape or size, eyes or ears, human nor animal- an infinite celestial omnipresent omniscient energy.