The poll is asking about how fast it should scale (ie. the ratio).
Which may not be THE right question, but it's certainly A right question.
If you have a question you think is more important, then ask that as well. This thread doesn't prevent you starting others.
Okay, I realize all of that.
My point was that hp don't exist in a vacuum. They exist to balance an equation.
Assume the oversimplified form of:
(h)p = (d)amage
Any discussion that considers how h will change should therefore also consider the implications thereof upon d.
Keep in mind that the above is, again, oversimplified. There are numerous factors to consider. Just for starters, the number of hits a character should be able to take (I believe the prevailing number from that poll is 3). Thus, our equation becomes:
h = 3d
I mean, it's all well and good to say that you'd like to see hp double, or triple, or whatnot, but I think it's very important to consider whether that leaves the designers with enough room to include meaningful changes in damage as levels increase. Personally, I'd like to see monsters gain +1 damage per level, because it creates a smooth basis for clear improvement.
Based on the equation above, that would indicate that the fighter needs at least 3 hp per level (after 1st), or [1st level hp] + 27 at level 10. That would be a doubling if the fighter starts with 27 hp, an (approximate) tripling if he starts with 13 hp, or a quadrupling if he starts with 9 hp.
However, 1st level hp shouldn't be ignored here. In the first case, the average damage at first level should be 9 (~1d8+5), the average for the second example should be 5 (~1d6+2), and for the third example it should be 3 (~1d4+1).
Of course, the above is very rough. It ignores a number of important factors, such as healing. I offer it simply to illustrate my point. The reality is that you're not just discussing hp ratios, but also the typical damage output of a level 1 monster as well as a number of other significant factors.
To me, it's like discussing the number of cylinders a car should have without first discussing whether that car should be an SUV or a supermini.
In my opinion, it's important to keep these things in mind during such a discussion.