Pilling T-Shirt after first wash

I just got a T-Shirt from J.Crew and have worn it maybe 3 or 4 times and just washed it inside out cold water, and I noticed pilling on the back lower part of the tshirt. I never looked, so this may have happened before the actual washing.

1) Why is this happening? Is it from me wearing it or washing it and can it be avoided?

2) How can I safely remove this?

No help with this?

I love the cut and the feel of the shirts more than any other brand I've tried. And my question pertained to shirts I"ve already bought, so telling me to buy another brand doesn't really help