There's no such thing as the left or right, full stop.
Plotting a 2 party system like in US/AU onto that spectrum is futile as it is, but it's comical when it's applied to Europe where no 2 party system exists at all. We form multi party coalitions and reduce presidential elections to run-offs. Society pulls in a lot more directions than 2.
I understand that lazy folks love a shortcut, but in turn, they should understand that others can easily mistake their laziness for being a moron. Much like the parties they describe being easily taken for being "right" and "left" depending on what criteria you want to apply, what you want to ignore, and the purpose you're trying to serve.
In the case of the trolls, professional or just your average unemployed loser with nothing better to do, the purpose is: aritculate sides, define it as 2, put them against each other, stoke the fire and get them as angry at each other as possible, watch/capitalise on the discord.