Ask yourself this, how are we able to freely talk on this forum? Do you think that the views expressed on here are subject to potential prosecution and imprisonment? Of course they're not, it's never going to happen even if something said was illegal. It would only go this far if something said was actually very serious and got reported.
The greatest irony is that you are freely able to speak on here about the criminalisation of free speech. You are freely able to criticise the state and its use of the law to reign in people who a jury would judge overstepped the mark. You have offered no comment against what people have actually said which is awful in places. You're just basically arguing that people should be able to say anything because otherwise where should the line be drawn?
You only have to read into what some of these people have said so the question you should really be asking is should we legalise racism and hate given its apparently just free speech? Should we allow people to stand in the streets and antagonise minorities? My view is no we shouldn't, a line has to be drawn, we should also consider urgent prosecutions to act as a deterrent when that sentiment drives violence and riots which it did.
Similarly, it isn't free speech to speculate upon who committed a crime purely because you want to enable a means to antagonise and persecute Muslims. It would be perfectly okay to say that I think X geezer did it, it would however NOT be okay to say I think that X geezer did it because he's a Muslim and look everybody all Muslims are X.