There are so many debates in the world about idol worship and even wars are fought throughout the history.Those against idol worship feel compelling need to correct others even by using brute force.
At the crux of all religions, the form of God as we call it has been named as one with no form but praised with several different superlative attributes.
Vishnu, Shiva or Shakthi are some of the examples of this manifestation of attributes in case of Hinduism. At the core of the Hindu philosophy, it has been very clear from age immemorial (in Vedas), that the God is one single Paramatma.
Different philosophical schools like advaita, vishishtadvaita, dwaita, dwaitaadwaita, achintya bhedabheda and others have all only differed from the point of view about the relationship between soul and supreme soul ( atma And paramatma) and was not about the forms of God.
So the fact that at the core of the philosophy, Hinduism perhaps has been clear about the form of God or lack of it, much before several other religions proclaimed.
So with this in the back of our inquisitive minds, now lets try to understand the importance for idol worship to see whether one should do it or discard.
First the simple answer is that it is all about the need and the necessity of the worshiper.
Think of an idol as a torch light or a guide while traveling for the first time in a route towards your destination. While all going to the same destination, each one chooses their path to the destination based on personality traits, physical and mental conditions, barriers, cultural ethos etc.
A sect/religion is like a path towards this destination. A guru is like an expert guide to walk you through this journey. If some one can see that a particular path is comfortably lit they should simply take that path.
While traveling we prefer to have an enjoyable and safe journey in addition to reaching the destination. Idol worship is like a guiding light on the way to that destination when in dark to save from rocks, thorns bushes that might exist. It is especially useful for the first time traveler traveling in that journey.
It is totally fine if one does not need any light, but those who in need goes into the journey holding the light to gain the confidence.
You still have an equal probability of reaching the destination with or without using the guiding light, but the use of it may make the journey much easier and assuring for many people.
The form/idol you choose depends on the personal preference similar to how different people choose different types and shapes of torches based on what is convenient to them.
So there is nothing that is incorrect in idol worship and it all depends on the traveler, some may need it and some may not.
However it is better to have one when you are not an expert guide through the darkness than be arrogant, blinded and keep finding fault with other torch bearers.
It is a matter of personal choice and for a novice and beginner traveler a very useful aid to get that reassurance of success.