After 12 years in Galapagos, frequently for months at a time, my experience tells me your interpretation is way wrong. Ecuador, and especially Galapagos, is very much a tip culture. Just because people don't let you know how they feel about you not tipping doesn't mean they don't let others know how they feel about you not tipping. Ecuardorians are a very warm, friendly and non-confrontational people. It's not their way to complain. They will just absorb the sting of disappointment rather than make you feel uncomfortable.
Among the older dive guides, it used to be almost a given that if they knew Europeans were coming onboard, they ended up 'sick' that week. It's not uncommon for a crew to blame a lack of tips on the guides, as though it's their fault. I hate to see guides beg or pressure divers in any way about tips. I think it backfires. I know it makes me uncomfortable.
What I tried to do was outline how essential everyone on the crew is to the success of your trip. People tend to overlook all but the guides. 10% has been a recommendation since long before I was here. Tipping is most definitely discretionary based on the service you received. It is in no way obligatory anywhere. But where it is the custom, I still think you should respect the culture you're visiting rather than the culture you come from.
PS..I just looked at the site you linked. It was started by Germans, a non-tipping culture.