I wouldn't really say regular ballpoints are popular so much as ubiquitous; people use them because they are everywhere, and often times they are free or next to free. Among persnickety users of writing instruments, ballpoint pens are often frowned upon, at least until recently.
Japanese pen manufacturers are currently competing in the market of super-smooth ballpoint pens. I think it can be safely argued that the Uniball Jetstream really initiated these better-than-average ballpoints, and within the last few years, Pilot, Zebra, and Pentel have also released new lines of ballpoints going after the Jetstream - and I'm glad they did, because now there are some amazing options in the ballpoint pen world, such as the Pilot Acroball (see written review below).
As you can see in the review, I noted that the Acroball does have a bit of white space in the lines, and there was a very small amount of globbing, but I don't find it to be a problem given how good the pen is overall. If you have tried the Pilot Dr. Grip, the ink in this one seems pretty similar, if not a little better.
The smoky black on this pen looks cool, and the construction feels very good.. This is a very light pen, so as long as you don't mind light, retractable pens, chances are you will enjoy this offering quite a bit. As I said in the review, the herringbone grip is excellent. I have slowly been replacing all of the cheap ballpoints in my family's pen cups with pens like this, and it is amusing to hear the occasional "Hey, this writes really nice!"
At $2.25 on Jetpens (no affiliation), it is easy to recommend this one. Go try it.