Yeah but the scale is the problem.
The message coming from the right is that Corbyn can't be trusted with running the country, it would be dangerous, etc. Essentially the same rhetoric they threw at Miliband, Blair and Kinnock. People expect it, and most of the swingable voters can see through it.
The message coming from the left in this election however is essentially **** the Tories, they're murderers and anyone who would even consider voting for them is a Nazi. People weren't expecting it and most of the swingable voters are a bit alarmed by the aggressive/violent nature of the attacks, plus most can see through them.
The right are essentially saying "if you agree with us more than them vote for us" while the left are saying "you should agree with us and if you don't then **** you Thatcherite scum". Ironically it's the die hard Corbyn supporters who have done more damage to his/Labour's chances than the Torys have.