Why Roaming Costs Are Unjustified

One of the idiotic complaints I've seen from users living near the border here in Vancouver (around the White Rock/Blaine area) is that they get "gouged" by the mobile phone carrier for roaming charges after picking up either Rogers, AT&T, or T-Mobile depending on where they are. And when the carrier forgives the bill, the users then complain that the company should do more to stop signals from over-powering the other, forgetting that these towers are built to keep that in mind.

I asked a friend of mine who used to live in the area what he did to prevent being charged for roaming and he basically told me that while he could manually set his phone phone to his carrier (Rogers), he chose not to because it was far easier to just move around the house and wait for the roaming to stop as he would prefer to let it switch when he does cross the border since it's only 2 KM away.

It's a bit ineffective as I keep my phone locked to my carrier's ID but how can people already aware of this problem not do the same? Roaming charges are garbage sometimes but there has to be a level of responsibility on the customer to keep an eye on these things if they're close enough to another (foreign) network.

I wonder why there isn’t more roaming competition. Roaming users actually have a choice of carriers: my AT&T phone will never connect to a non-AT&T network in the US. In other countries there are usually 3 or 4 networks different networks I can connect to. (My phone is SIM locked, but I’m roaming with an AT&T SIM.) Why doesn’t one of those advertise to travelers and say “Use Carrier X, we’re 90% cheaper”. Is it because they can’t convince AT&T to pass on the savings?