I personally think so. I find that positive quotes can be very inspirational especially when feeling surrounded by negative things going on. They can bring some optimism and for me some quotes an put things in better perspective.
Quotes can sum everything up perfectly in one or two sentences - there are some 1500 word articles out there that don't get to the point or convey the same sort of meaning. That's why I like them. They're short, simple, to the point, and yet beautifully poignant.