Allstate is losing money like it's going out of style. I am not sure of the reasons why, it could be Katrina, it could be operational, but they are not doing "well" at this current time. They seem to have recovered a little bit, but it's always going to be at the policyholders expense.
Back to the orginal topic of insurance rates dropping at 25.
A few years ago the auto insurance industry was plagued by unfair rates. The reason being that most insurers grouped drivers for the ages of 18-24 and 25-60 to be the same. Therefore there was only two basic age brackets. As of lately most insurers have gotten a better handle on it, rating their policy holders according to age, not just a group of ages. Therefore drivers at 25 no longer see the decrease that they once did. Before, when a driver turned 25, they got the 60 year old driving rates. Now they get a more accurate representation of age.
The idea is that it is not fair for all of the older crowd to pay for all of the younger crowds misfortunes. The older you get (to a point) the less you wreck, that's blunt honesty. Now rates are better associated with the risk that they take on. Insurance companies are better matching risk to premium and that's what policyholders should want.