My husband and I were Evangelical Protestant for the first 47 years of our lives before converting to Catholicism.
The main reason why there are no crucifixes in Evangelical churches is that we serve a risen Savior. He’s no longer on the cross. Ask any Evangelical Protestant and they will give you some variation of that answer.
As for the “idolatry” issue–that’s not it at all. I’ve never heard that, and neither has my husband.
For some Evangelical Protestants, the issue with crucifixes is “graven images.” There are certain Evangelical Protestant sects and organizations that teach that ALL images of Christ are forbidden. J.I. Packer (RIP) was a highly-respected and popular Evangelical Protestant leader who taught this. He even went so far as to say “no pictures” of Jesus in children’s Sunday school and VBS material. And of course, no actors should ever portray Jesus–these groups would be opposed to movies like The Passion of the Christ or ANY play or movie in which a mere man portrayed Jesus.
Now don’t get the wrong idea. It’s not just a legalistic adherence to one of the Ten Commandments, although these verses are cited.
It’s far deeper than that. These “anti-God-image” Christians believe that any “image” of Christ is not worthy of Him, but rather, are mockeries of the Lord. So this mindset is actually extreme reverence for Jesus Christ.
It might be worth keeping this in mind if you are talking to Evangelical Protestants who seem offended by our images and artwork. Many Catholics are convinced that their beautiful church naves bring honor to the Lord Jesus through all the art work and sculptures. But this is not the mindset of certain Evangelical Protestants, who find these places offensive and insulting to the Lord Jesus Christ because of the images, including and especially the crucifix, which depicts a dead Christ instead of a living Christ.
And interestingly enough, I heard a priest speak once at a conference, and he said that images of God the Father are very rare, and the reason he gave is pretty much the same–that we can’t seem to create an image that is “worthy” of God the Father.
I hope that Catholics will respect the desire of these Protestants to be completely reverent to Jesus.
And I hope that this information helps answer the OP’s question.
Interestingly, more Evangelical Protestants ARE wearing or displaying crucifixes nowadays, as they learn about the theology of the Sacrifice of the Lord Jesus on the cross.
One last comment–back when our daughters were still at home and we were all happily Protestant, our older daughter, who was about 13 at the time, said, “I don’t think our church should display a cross. To me, it’s like displaying an electric chair or a hangman’s noose–eugh!” Boy, did that statement ever make her Daddy and Mommy think! That daughter has since converted to Catholicism, BTW.