I don't know about anyone else, but I got sick of 6-8 minute bot matches where I don't even complete one core item for the build I'm trying out, so I don't try to win the matches anymore - I just try to get as much gold as possible and not lose. So, yes, sometimes the bots will 3 or 4 cap us, because I'm letting them and I will get more gold by staying where I am and farming minions or bots, then going up and grabbing those points later when the spot I'm at is all cleared out or I run low on health/mana. Plus, the more points the bots have, the longer the game will run. You may have teammates who are doing the same, or they might just be that bad.
I'd be pretty happy if I was in the OP's position.