Youre reaction is actually a perfect example of an anti-socialist movement based on denunciation than one on arguments. You go from socialist to communist to extreme left winger withought distinction, only to try to marginalise his position on grounds of how many one (mis-)perceives would support that.
Ive heard people argume many times on this forum that Corbyn would be obviously bad, the problem is that it's practicly never backed by any argument though. Could be that Corbyn is bad, havn't got enough to decide, it's not that those who trash him tend to actuall explain why. It just look like gratuit denunciation as a concious tactic and it's understandable why that could be used but then it also becomes the obvious explenation for that nonsense. Aka, the right don't want the left to win, so they don't mind to create lies and hyperbole's on their rivals because it is i their interrest. So they start to trash on Corbyn and hope that the same kind of repetition that works in advertisement will work in that instance. In fact, the UK is only just a bit behind on the US when it comes to creating a culture of trash talking politics.