The principle is really good but the concern, especially on sites dealing with politics, religion or controversial issues, comes from the fact that people write negatively on the basis of the substance and not the form which bias the results. Sites that are quite safe are therefore decked with negative ratings that would suggest a security risk.
That's why I stopped to use WOT after long time of using it. And yes I remember having trouble with the logging system, maybe a conflict with another privacy/security add-on I use.
However it could be a good measure of protection but remember to use common sense.