As an American who travels to Europe a lot (not in the last two years

) it helps to do your homework. Americans (in general) are terrible vacationers. A lack of perception of local culture and sense of entitlement are often mentioned. I try to do as the Romans when im a tourist. Its not perfect and most people will appreciate your questions because it shows you care.
If some locals have the opinion you shouldn't come at all, that is unreasonable. If it was really harmful, and a majority thought so, it would be illegal to travel. A little research upfront can make you a welcome visitor over another jerk traveller.
While I agree that it's important, and that it's also important to consider eco-tourism as much as possible, and contact with people, unfortunately, what you are stating above is simply not good enough. The government might not ban tourism because it's a huge source of revenue, but local people might feel very differently in specific regions, where tourism is sort of forced upon them. So unfortunately, it's hard to work out.
The only way out that I've found is to find a travel agent that you can trust. I have had the luck to find two, one for around mediterranean (ended up bivouacking with camel riders right inside Petra, amongst other incredible things) and one for asia/pacific (ended up staying for a few days with my daughters in a village in north thailand with no running water or electricity, taught a lot to all of us). If you can trust them about their contacts, and follow their advice, you will have a much better experience and, as importantly, so will your hosts in the country.
Also, you have to take into account that there are jerk travellers but also jerk locals. Anecdote domain here again, but when my south african customers came to visit France a while ago, they told me that, when speaking to people on the street, they started by speaking Afrikaans, and then switched to english, to show that they were not americans, since the french local had a tendency to act like jerks towards americans...
Anywho, to bring it back vaguely to the subject of the thread... Well, I honestly can, mea culpa.