Wow, it's kind of surprising so many people seem to have trouble!
Ever since I was a kid, I could dry-swallow even large pills or multiple ones at a time. I'm the only one in my house who can and I can't recall any time I've had a problem with them. I was sick a lot when I was younger, so it was definitely a good skill to have. And, honestly? I hate liquid medicines -- the taste lasts so much longer. If I need to take medicine, I'll always opt for pills if possible.
Pills are smaller than most bites of food people swallow, so I wonder how much is the texture of the pill and how much is psychological.