Idol worship and the many gods of Hinduism had been a source of attack on Hinduism and also of dis-information about Hinduism.
The following links provide a concise explanation on these and also on the rationale of Temple worship. Other issues on the state of temples also are covered.
In other religions there is one God but he exists outside the his creation.
But in Hinduism Gods are many, and that is not a defective version on God. It means that God is in all things and can be perceived as anything that one wishes. It means God is in everything and everything is in God...
So goes the rationale of many gods of Hinduism
Significant Role of Temples and Religious Institutions (PDF)
Sustaining Dharma Through Mandirs (PDF)
Government Control of Temples in India (PDF)
Denial of Religious Freedom to Hindu Community in India (PPS)
Hindu Dharma Acharya Sabha (PDF)
Hindu Jewish Declaration (PDF)