[searine]

You and the person you were replying to are confusing two kinds of GMO crop:

Pest-resistant (kills bugs) and Herbicide-resistant( makes the plant robust to chemicals which kills weeds)

You're right about refuges, they only slow things down. To truly prevent resistance genes in pests from appearing, you need multiple modes of action. This was used effectively in HIV treatment. The virus was developing resistance to AZT treatment alone, eventually new drugs came along and patients were treated with 3 or more drugs at once. Multiple modes of action makes it too hard for the virus (or pest) to adapt in time. We don't really have multiple modes of action in plants yet, but one day, maybe?

The person you were replying to was describing herbicide resistant crops, which are sprayed (sometimes oversprayed). This isn't so cut and dry as they describe though. Things like glyphosate are much milder compared to older herbicides and GMO crops encourage things like 'no til' agriculture which greatly improves soil quality. So we're still spraying, but it's better, and has ecological benefits.