I think you kinda answered your question in your question.
I, too, wouldn't paint oak or popular or ANY wood for flooring unless it's pine strips or sheet plywood (which is mostly pine.) Reason? As you said, it's too expensive to cover with paint. Oak, Popular, and Maple and so on have a beauty that's to be seen. In short, they're stained; not painted.
Now, let's assume you lay unfinished pine on the floor, and then paint it. Let me tell ya that in short order (could be a few months, could be a couple of years), you're gonna see 'wear marks' from where people walk. Yes, there are durable paints that hold up well under-foot but white will show the slightest dirt, scuffing, and 'nicks'. Of course, the darker the paint, the darker the room (and the darker the room, the more of an 'illusion' you get that the room is 'small'.) I know where you're coming from.
I'd like to suggest you look into Laminated / Engineered Flooring. (For this discussion, I'm not suggesting Pergo.) Go to Home Depot or Lowes or any Home Center and ask about it. Some of these floors can be refinished, some can't. Point is, you can get the look of real, solid wood for less money than a solid wood floor. Be aware that, unless you're removing some of the existing flooring, this type of installation will RAISE the floor, thus, possibly creating a 'transition issue' with other rooms as well as possible door opening/closing problems. IF you go this route, find out where you're new floor will 'rise up' to BEFORE you install. This way, you can address room transitions and closets and so on BEFORE hand.
As for a 'hard floor' and 'denting', I suggest an area rug under your table and chairs. I'd do this for a painted floor OR a hardwood floor. There are some really nice Arabian rugs and such. IF you can find them with the pre-installed rubberized backing on them, that's what you want. If you can't find the backing pre-sewn on, you want to buy the backing SEPARATE to lay under the rug so the floor doesn't get all scratched up from the back of the rug. You see, most ALL rugs are meant to have a padding under them 1) to protect the underlying floor from 'damage', 2) keep the rug from slipping, and 3) for softness. The backing I'm referring to IS sold separately and does 1, 2, and 3. Since you'll have a table and chairs on top, this 'weight' will prevent the rug from slipping off of the backing.
Maybe others have more to say on your original question. Me? Personally, I wouldn't paint my floor no matter what room it's in. My best to ya and hope this helps.