I text and walk at the same time every day and have no problems.
But some people just can't multitask very well. And that's okay, it happens. But if you're incapable of walking and texting at the same time, don't try to do it. You just end up looking like an idiot.
This is especially unacceptable on stairs. In hallways or on sidewalks, etc., there's usually plenty of room to walk around a person. But on the stairs, you end up creating a traffic jam and that's just no fun.
I was leaving class the other day at the same time as another girl and she just kind of paused on the verge of stepping down onto the first step. There were people coming up the other side, so there wasn't really anything I could do.
She was pausing for an awkward amount of time, so I eventually kind of squeezed past her, but we were in pretty close proximity, so our shoulders brushed a little. This makes me look like the rude one, but she's the one who stopped at the top of the stairs for ten seconds to finish a stupid text message.
Just saying, if you can't multitask, don't try to.