Mh, Martin, I think you generalized your own experience quite a bit.
You need to keep in mind that Italy is a very fragmented reality. Sardinia, in particular, for historical reasons, is often regarded as that island attached to Italy. The island itself regards its territory and power as almost independent, and rarely actively partecipates to the national debate.
Sardinia is largely exploited by Italian citizens as a holiday location, which is forgotten once you get back home, and by the government (or sometimes governments, considering the numerous foreign military bases placed on Sardinian territory).
Moreover you went to Porto Cervo. Porto Cervo is, more or less, the VIP fancy pantsy area of Sardinia, if not of all Italy.
No Italian would go to Porto Cervo to have a break, unless they want to show off and boast about how rich they are. Since, rapidly, the wealth of the country is converging in the hands of fewer people (similiar to the US situation, concerning the distribution of wealth), Porto Cervo is very little indicative of how Italy and mostly Sardinia really is: it perfectly expresses the behaviour of a certain irresponsible part of population.
I do understand the comparison between Majorca and Sardinia (both largely independent from Spain and Italy), but it's unlikely that the better economical situation of Majorca and, you say, even Spain is to be linked to "honesty pays".
First of all, it seems streched to deduce the spirit of a population from a bad (I assume you'd consider your stay in Sardinia as bad) experience; then it seems to me you forget that both the countries don't live on turism (without, of course, denying that turism is a great part of their economies).
The place where I felt most welcomed in my life was Finland (and people think finnish people are cold-hearted), but I wouldn't connect my impression to their economical situation so recklessly.
I am pretty sure you have been ripped off by the taxi driver.
I sometimes use taxi in Sardinia for work reasons and covering that piece of road should not cost you that much.
Occasionally you will find illegal (meaning non-certified) taxi drivers. Those are mainly people with a car and (sometimes) a TAXI simbol over their cars who pretend to be taxi drivers. I can assure you they do their illegal business in good will, but their prices are off the charts.
At the same time, you should pay attention when you pick a taxi. If they don't have the TAXI sign, you should decline their offer. A certified taxi has the price list hanged on the back of the front seats. The taxi driver has an id card in his car that proves he is an licensed taxi driver, and if he's outside the car, he has it with him and should be able to show it to you if you ask for it.
Also, it depends on the time when you took the cab. If you took it after 9 pm, the cost is higher, according to a (I think) 2001 law. I wouldn't say, in this case, that this is lack of honesty, as much as it's protection of the worker (taxi driver).
Lastly, about Silvio Berlusconi, although I doubt you really met people who visited Berlusconi's Villa (I am sure they told you so, but they might have been lying), you need to remember that once you're 18, in Italy, you're completely of age: you can drive a car, own a house, have sex, and vote (although you need to be 21 to vote for the Senato).
That being said, since the Procura di Milano recently filed a report (still to be judged in court) about Berlusconi having intercourse with underaged girls (17 I think) and given also the numerous ladies he's supposed to have slept with, I agree that this type of behaviour is despicable, especially for a Prime Minister.
I also need to point out that, according to his version, all these things never happened, and that until the court passes a final ruling, all these things remain only presumed.
So, in the end, both when it comes to good opinions and bad opinions, it's one thing to be stating facts based on datas, it is another when you conclude all-round judgments from a singular personal impression.
