Why does every poke stop say "this pokestop is too far away"?

All PokéStops & Gyms need to be within your vicinity (note the "radar ring" that radiates from your avatar, as such points of interest MUST be within that ring) for you to access. If the desire point is out of range, you'll get the "Too far away" note. This is based on your GPS location (or the WiFi hotspot you're connecting to, if you're not going through the cellular network) & it has annoyed me a few times being just a couple of feet out of range.

All you can do is just get closer to the desire PokéStop / Gym. If your avatar doesn't move closer, you may want to consider rebooting the game to force it game to update the GPS information.