An effective wheel diameter of X is the same regardless of the wheel size because it takes wheel size into account. Instead, the ratio of chainring teeth to sprocket teeth really is meaningless without knowing the wheel size. For most of us neither the wheel size nor the crank length varies so much bike to bike that it matters. A 26" wheel vs. a 27" wheel is equivalent to changing a sprocket from 27T to 26T. Compared to the overall range of available gears, this difference is (almost) trivial. Even more so for a 622 (700c) vs. 630 (27"). So effective wheel diameter is a good way to express effective gearing, though you could quibble with the use of inches instead of mm. (But hey, we use a mix of metric and English units for everything else on bikes, so why not gears?)

There is another, more subtle value in the use gear inches over tooth ratio, or any ratio whether corrected for wheel and crank size or not. It's a matter of how much comprehensible information is carried in the number. Most of us can visualize the difference between, say, 32" and 50" and 90". In fact, the first digit tells us most of what matters. However the corresponding approximate ratios 1.185 and 1.851 and 3.333 are gibberish.

I are a injuneer (and rather too highly educated in science to be useful to man or beast) so I'm quite at home with metrics of all sorts. But for sheer intuitive understanding, I stand by gear inches.

Now back to your regularly scheduled discussion of chainrings.