The money changers changed pagan coins for temple shekels which could be donated to the temple. Coins with images of pagan gods were not acceptable.
Those selling animals were selling animals which had been determined to be perfect and acceptable as sacrifices.
All of the merchandising going on had to do with temple worship.
The problem was (I think) that the merchants were ripping the people off and charging too much for their "perfect" animals and giving a lousy exchange rate for the money and they were doing so with the permission of the temple leaders who, undoubtedly, got their cut of the profit.
To assume that, because of the merchandising of religion, the temple was the "mother of Harlots" is, I believe, too great a reach.
Also, keep in mind that, when John wrote the Revelation, there was no temple. It has been destroyed by the Romans about 20 years earlier.
iakov the fool
We know the woman sits on many waters and the waters are nations and peoples. It can only be the filthy ungodly governing body of each nation that is the mothers little harlots that lives in luxury, all sitting on God's throne, playing God, telling people what they can and cannot do through there man made carnal laws and people worship mans system, even if they don't know it they all worship and obey this filthy world system they have the mark of the Law on there hand and forehead.
And people think Moses gave a heap of laws, he only gave a couple hundred to put everyone in a ball and chain. look at what you live under today, probably a couple hundred thousand, you can barely even fart without breaking the Law because someone might be offended and the Law is going to bring world peace.
And then we have Christ.
"Blotting out the handwriting of ordinances that was against us, which was contrary to us, and took it out of the way, nailing it to his cross, and having spoiled principalities and powers, he made a shew of them openly, triumphing over them in it."
Think about it. God put his law and they used to literally walk around babylon with the written law on there hand and forehead as a sign.
"Fix these words of mine in your hearts and minds; tie them as symbols on your hands and bind them on your foreheads."
"And it shall be for a mark unto thee upon thine hand, and for a memorial between thine eyes, that the Lord's law may be in thy mouth: for with a strong hand hath the Lord brought thee out of Egypt."
"Behold, the days are coming, declares the Lord, when I will make a new covenant with the house of Israel and the house of Judah, not like the covenant that I made with their fathers on the day when I took them by the hand to bring them out of the land of Egypt"
Christ fulfilled the Law and done away with sin. The new covenant go back to the garden and walk with God. Love God and Love others and if one falls there is the medias who has already taken away the worlds sin. But man still follows the Law and has the mark bound on there hand and forehead.
Look at many nations in this world, if people speak out against there governing authoritys and the Laws they are under and dont worship and follow it, they are persecuted, thrown in prison, or killed.