I don't underestimate Argentines. I just know that in the little corner of Argentina I live in the only place you see dollars is the one cueva in town. I also doubt the majority of the 40% of Argentines living in poverty have much daily experience with using currencies other than ARG pesos. I don't think it matters what country it is, you change a nation's currency and there's going to be a learning curve. Back in the 70's the US tried changing from Imperial to Metric and it went over like a lead balloon - all new highway signage to supplement the Imperial signs, barely anybody could wrap their heads around using the Metric System, all the money spent on signs wasted when they discovered it didn't work. Different animal, sure, but the same concept. I doubt anyone not already currently handling US currency on a daily basis is able to recognize well done counterfeits; knowing about watermarks and other protective markings, paper feel and weight, etc. Peru being so close would seem to be an obvious opportunity to bring a large amount of counterfeits into a new system.
When I first moved to Peru a cab driver passed me a phony large denomination bill as part of my change. I was in a hurry to catch my flight and the currency was still new enough to me that I didn't recognize it until someone I was trying to pay had pointed it out to me. It had nothing to do with nationality or underestimating anyone's intelligence. But I'm not arguing that an increased opportunity for counterfeiters is one of the most important reasons to be cautious when considering abandoning one's currency and any control one has over policies tied to currency. It's really just something to consider as an aside.
I'm not following the resisting change argument. If someone proposed a policy you either flat out didn't like or were cautious about would that make you resistant to change and would you accept someone's "resistant to change" rebuttal to your opposing points as being valid, or just vague and off topic? Don't like a socialist proposal such as single payer healthcare or free University education? - why do you keep looking for every excuse under the sun to resist change? Maybe it's not that you're resistant to change, it's just that you're simply unconvinced, undecided, or for reasons having nothing to do with resistance to change are opposed to the idea being proposed?
Change simply for change's sake doesn't make sense. Change to something else simply because it's different from what exists now only makes sense if the change is better or you're literally facing imminent death if you don't make a change right now, fully realizing that even if you still may die, at least you tried - jumping from the fourth floor of burning building with no help in sight. Dollarization as a concept can be made to sound swell - just like many other economic policies that take research, knowledge, and understanding to fully grasp. I think politicians take advantage of the complexity of many issues to put forth very simplistic solutions, figuring the overwhelming majority of the public won't understand the issue but will like the sound of their proposal and couldn't be bothered to studying the issue. International trade and trade agreements - barely anyone understands the nitty gritty of them. But everyone understands the concept of a tariff and so without any further consideration they think a proposal for tariffs sounds like a great solution - whether it turns out that way or not (and it usually only hurts the population of the country that applies the tariffs since the producing country passes along the cost of the tariff through increased prices).
My preference is for careful examination of what effects dollarization would actually have, how has dollarization fared for other countries that have taken that route, etc. I realize it's been done in less sophisticated countries (one could ask "why do you underestimate them?"), but in at least some of those countries the results weren't what was expected and weren't all that rosy. Some prefer to paint study and caution as resistance to accepting something blindly because it sounds good and must be better than the current situation. Dollarization may well be better, but I need to be convinced by an argument much more substantial than "why resist change?" And isn't "resistance to change" usually something you hear to describe conservatives who want to conserve the status quo and make changes cautiously? And it's the liberals who want to change things from how they were/are? Strange times we're living in.