Find something better than Wikipedia, which can be written by anyone with a big agenda and a tiny brain.
Look how it contradicts itself, for cryin' out loud:
"Traditionally, the Left includes...and anarchists."
"The contemporary Left usually defines itself as promoting government regulation of business, commerce and industry;"
Now, how in the heck can you have both "regulation of business, commerce and industry," and "anarchy" which means "a state of lawlessness and disorder" and "having no government leader?"
That is the most stupid writeup I've ever seen, and I've seen some stupid ones from Wikipedia.
Look if you want to reinvent the wheel, at least have the common decency to call it something else. I know you can find a definition that fits your terms, you didn't invent this deception, that was done at some right wing thing tank. Wikki is subject to critique from all sides, I find their defintions to be pretty great and accurate.
I'm not an anarchist but I suspect, since they don't like rules and orders, they see business as the major maker of order, and the governments of the world as being the sock puppets of business, so when the sock puppet slaps its maker they cheer and line up on the left. They see the right as supporting these businesses, and you do! In no way could they every line up with the free market people of the right who think capitalism is a perfect savior in religious terms, now could they? They see capitalism as a big scam, where the players work together to rip off the non players, and these players hire soldiers and cops to police the system and keep it working for the benefit of the folks on top. And in addition our anarchists are very for the poor and working classes of the world, and to tell the truth the right really hasn't done much for them. I would also imagine the rights group think would also turn turn them off. And then to add a bit more reason, they have a world perspective not just a nationalist one, and they actively resist the G8 and G20 where capitalism is set up for export worldwide.
Frankly, I don't see any mystery here at all.