Sorry, I didn't word that very well. What I mean is that in our experience when we stay in a hotel, we very rarely leave the hotel and so do not get a proper feel for the country. If you go self catering, then by definition you have to get out the house to do shopping, etc - and thus you get a taste for what the island is really like. I know at hotels you can go on package coach tours and stuff, but it is not the same as hiring your own car and exploring the country yourself. Does that make sense?
Also, this way, most of your money goes into the local community (who in Barbados are generally poor) as opposed to the US corporate run hotels who keep the money for themselves and don't give a shit about the rest of the country or the negative effects tourism has on the country.