When a nerd gets his or her hands on a new game, it doesn't take them long to figure it out because they've played so many games they know how to ask the important questions:
What does this game want me to do?
What loopholes has the game provided for me to exploit?
How do I make my character more amazing than needed to complete the game?
Pokemon Go wants you to capture pokemon. The game's mechanics are built around this singular mechanic. If you do nothing but capture pokemon all the time and ignore the gyms you'll have so many resources you can max out the strongest pokemon without ever having been in a pokebattle.
Loopholes are knowing pokemon trivia and capturing tons of pidgey and rattata (or whatever other pokemon is super common and quick to evolve) Also, if your office is within range of a pokestop you pretty much have no reason ever to buy pokeballs.
Besides paying for it, again the only thing you can do to become more amazing than the game expects you to be is to literally spend all day capturing pokemon instead of having a life and capturing pokemon whenever you're bored
Pokemon Go is literally just about the throwing mechanic that's the only skill you need to concern yourself about.
Too Much Exercise
A real nerd hates exercise but not for the obvious reasons. Sometimes you'll see a really jacked or fit nerd, but his/her way of getting in shape is precise and no nonsense. He reads just about everything on fitness nutrition and proper fitness training and doesn't spend a single second eating or lifting in vain. Pokemon Go has you walking around aimlessly. A nerd gets tired. He ain't got time for all that. Gaming is a time for relaxing and sitting on one's ass while pushing the limits of one's puzzle solving brain.
Hot girls are out playing pokemon and dying to talk about what cute pokemon they captured. They want to talk to a nerd who can teach them stuff abotu the game and tell them the answer to "is this pokemon good? this blue thingy?" A nerd gets confused. His videogames are his escape from either his shyness or his insecurities with the opposite sex. Sex aside, the idea of going in groups to find a charmandar is just not what gaming is about.
Too much of a fad
Pokemon Go is in a nerds mind already fading fast. It doesn't have the depth of a real pokemon game and so its going to sharply decrease in popularity very soon. We've been at this long enough to tell the difference between a game with replay value and a game thats a gimmick
You can't play pokemon go for hours straight. it's not built that way really unless you're willing to shell out real cash for pokeballs. A gamer loses himself in a game and so hours don't really matter but with pokemon go that escape is cut brief by a need to wait and refresh supplies