VidaNaPraia

Rio has a unique spirit and culture. Much of the culture originally came with the settlers from Bahia. It shows in the vibrant music scene and strong neighborhood organizations to which cariocas have allegiances. There are also wonderful natural areas within the city. A visitor who does the research to discover this can spend an amazing time in the city, well beyond taking the iconic arms-out photo under the Christ statue.

I live among Brazilians in the US and in Brazil and cannot generalize about "every Brazilian I know" because there are simply too many. But.....
Middle class Brazilians, such as those in Sao Paulo, and often of European lineage, generally have pretensions to first world status. Many regularly denigrate the poor, the majority of whom are of color, from the northeast. This is culturally, racially and historically based.
Many lower middle class Brazilians are not well traveled and are afraid to venture out of their familiar settings. In my experience, they often go so far as to impede a foreign visitor from sightseeing freely, reflecting their own timidity. Small town Brazilians are often intimidated by the large cities.
These factors contribute to the expressed prejudice you have pointed out.

Rio is also unique among Brazilian cities in that the poor neighborhoods sit on the hills overlooking the richer neighborhoods, in very close proximity.
There is indeed a severe economic crisis effecting the entire country. There are now more people thrust into a desperate situation. Some of those may not have the moral compass we would desire them to have, but that is true in most places in the world. However, most cariocas and other Brazilians are friendly and helpful. Jeitinho Brasiliero is a fact of life in Brazil, so no Brazilian who uses it and is influenced by it, from the top to the bottom of society, can be said to be honest.

As to "feelings" of safety, I am female. I am vulnerable anywhere, in any country or situation, whether retrieving my car from a parking garage or sleeping in my own home or walking in front of a fancy hotel. This is a day to day reality in the US or elsewhere.
Maybe this is a big shock and surprise that male foreigners in Brazil discover for the first time, that they are vulnerable too.
However, I have been traveling regularly and widely, for long periods at a time, in Brazil, and have lived here for quite some time as well. While I do not look particularly "Brazilian", I have never in a couple of decades encountered a problem with crime of any kind.

I would encourage anyone, such as the OP, interested in a business or vacation trip to Brazil to do their due diligence. Do not flaunt your belongings where people who may not have your advantages may be tempted by them. Develop a way to be vigilant without being paranoid, as you may observe cariocas seamlessly do.

There are now guesthouses hosting foreign visitors in the Vidigal communidade whose entrance is across from the Sheraton, and foreign guests have patronized the shops and restaurants there. But the Sheraton is indeed a longer journey from the main sights and tourist bars/restaurants than other choices.
I agree though that, of the properties mentioned, the Marriott would do quite well for the OP and any future readers of this thread.