There are many reason why many protestants would look upon your question as 'Why is idolatry wrong?' Although to me your question sounds sincere.
The first thing to keep in mind is an idol is nothing in and of itself. (1 Cor 8:4) Having even a golden calf in a church would not be wrong in and of itself. Though in the Old Testament certainly any object not originally designed by God to foreshadow the gospel was forbidden from the temple of worship.
Secondly any image meant to personify the invisible God is degrading to his glory and forbidden in the ten commandments from being used to facilitate worship. (Ex 20:4)
Third, the golden calf was invented just after receiving a covenant and was made not to replace true worship but to facilitate it. Exactly like the sudden exaltation of Mary and the Saints after the second covenant. It was not only in the time of Moses that the golden calf was mixed into true worship but Israel (as opposed to Judah) regularly restored that corrupt mixture as a hallmark of its apostasy. (1 Kings 12:28) Protestants generally view the Catholic and Eastern ancient churches just like Israel in this matter. This is part of why they repented.
Fourth possibly the most disrespectful of the priesthood of Christ is that these 'cherished loved ones' are loved. They are presented as objects (with characteristics similar to pagan patron idols in the local region that they were first established) that have more empathy to particular difficulties than Jesus. The basic idea is that as carnal churches can't attract people with faith in Christ as the only one who can empathize with us as our priest. (Heb 3:15) The carnal attempt to appeal to pagan masses, is by replacing their idols with Christian versions, of the same thing. This mixes their paganism with the worship of God, i.e. more of the golden calf repeated.
Conclusion: Blocks of wood, and even really liking them as works of art, is not generally condemned by anyone. Using them to facilitate worship is considered idolatry by many. The example about the cherubim spreading out their wings is different as angels were not to be invokes to facilitate worship. In fact if angels were to facilitate worship their faces would be open to an assembly but actually they were in the most holy place (a place one could not enter) with 'their faces one to another'. 'Toward the mercy seat shall the faces of the cherubim be.' (Ex: 25:20) That is, they represented the heavenly view of angels 'upon the merciful atoning work of Christ', taking away the condemnation of the law, covering it up with his blood. The art implies a 'looking away' from angels to Christ, not the other way around. Our attention to 'loved ones' in worship is the quintessential idolatry as understood by many Protestants. Worship is viewed as our attention to 'The Loved One', not loved ones.