It's a summoner spell dude. It's meant to be used. Other than Smite, all other summoner spells are actually pretty good to take depending on what your play style is. If you're berating him for taking ignite, then you're not really using your head here.
Flash is generally the safest summoner to take because of how much utility it provides. All channeled or dash based abilities can basically be redirected using flash or have their distance extended to catch someone off guard. You can blink in quickly to give the enemy no time to react when you blow them up. Escape. Or try to finish them off with an auto attack. But not all champions can abuse flash to it's fullest capabilities.
Ignite is similar. Ignite is a safe guard to finish people off. It's an immediately accessible counter when you have a lane that is easily gankable but it has a Soraka as an enemy laner. It will keep Warwick from healing if you duel him in the jungle. And the cool down is decently short.
Exhaust is good on Junglers who have shit early games, incredibly squishy, or can't really abuse flash like Lee Sin, Vi, Gragas, or Jax. Exhaust + Red Smite will generally be a death sentence to anyone who gets hit by it. They can't get away and they lost 60% of their damage, the caster gets true sight over them, and they are taking true damage. The same can be said about Ignite + Red Smite.
Barrier is something you take when you're dealing with champions who can jump on you fast, and you're squishy enough to be blown up by a full rotation. Or you're a diver against a team with a lot of damage.