Radak, Malbim: El is in place of the prefix Beis, like "v'El ha'Aron Titen Es ha'Edus" (Shemos 25:21) is like uva'Aron. You built on the crossroads so it will be visible to all who pass.

Malbim (according to the Nimshal): They built Bamos and images on high mountains and the roads, and served different gods.

Radak #1: You were famous among the Goyim for your beauty that I put on you. You abhorred it and did not desire it, with your evil deeds.

Radak citing Targum Yonasan: You profaned your Kedushah.

Radak: Tesa'avi is Po'el Yotzei Shelishi (one causes a second to act on a third party). You make [your beauty] abominable to others via being Mafkir yourself to everyone.

Malbim: This is like a harlot, that amidst Zenus her beauty is made repulsive and her face withers, so she covers it.

Rashi: Because he compared [Keneses Yisrael] to a Zonah, he speaks in an expression of Bi'ah, in which one spreads the legs. Radak ? i.e. you invited everyone who passed to have Bi'ah with you.

Radak (according to the Nimshal): You were Mafkir yourself to serve every idolatry that all passersby will tell you about it.

Malbim (according to the Nimshal): Hashem's way departed from you. You were like disgraced Goyim who are submissive to all.

Malbim (according to the Nimshal): You constantly served idolatry.