Dude, it's June - go ride your bike outside. Turbos are for winter and rainy days.
I do ride my bike outside. But what if I've eaten a whole packet of jaffa cakes and I need to burn it off but it's too late in the evening for an outside cycle? Turbo trainer! What if I want to know how much power I put out because I'm a massive dork, but I'm too cheap to spend the price of a small car on a power meter? Turbo trainer! What if I want to ride my bike while watching Ghostbusters? WHAT THEN?!
I do ride my bike outside. But what if I've eaten a whole packet of jaffa cakes and I need to burn it off but it's too late in the evening for an outside cycle? Turbo trainer! What if I want to know how much power I put out because I'm a massive dork, but I'm too cheap to spend the price of a small car on a power meter? Turbo trainer! What if I want to ride my bike while watching Ghostbusters? WHAT THEN?!