These terrorists don't come out of no where, there are specific mosques creating them, specific communities shielding them and specific groups funding them. They're not just a bunch of religious nutjobs who one day opened their holy book and happened to come across a verse telling them to kill and suddenly decided to act on it. They're actually incredibly sophisticated in their propaganda, brainwashing and training. They're a highly organised group and not taking them seriously leads to what we have pretty much every week now somewhere in the world. I'm not talking about making the UK a police state either I'm talking about applying the same standards as they do to others on to them.
The comparison chart is also not a very good comparison, it's comparing an outright insurgency to a few terrorist attacks. Also just shrugging it off won't work either, these people will always find a reason to keep on doing it. There is no political solution to be found with them like the IRA, the phillipines isn't involved in bombing some middle eastern country yet they have an insurgency happening right now, trinidad and tobago didn't even have a muslim population percentage in the double digits when islamists created a coup there and that was pre 9/11. Indonesia was a Muslim nation but because the government was secular, islamists created an insurgency there decades ago too. Shrugging it off won't work when it's an ideological war, even if we don't get mad they're still winning adherants and sympathisers every day and just killing kuffars is a victory in itself for them.