I could give you 100 reasons why that "If they wanted it in, It would have been in 1st gen" rule DOESN'T work, but I agree, I doubt they'd make an EV page.
I was just dreaming for a color coded type thing for EVs.. Most EVs have a color, Second most, 3rd most. Like that...
Btw, doesn't a guy in the Battle Tower in Platinum tell you which stat your Pokemon has the most EVs in or something?
If they were able to make a stat page in these games, adding an EV page wouldn't have been that hard. :/
It's not like I'm saying they should have put Battle Frontier since 1st gen.
And having a color code for EV's wouldn't help you know how much EV's you have.
Anyway, you could just note them on a piece of paper or on Notepad.
The guy in the Battle Tower tells the highest IV of your Pokémon.