The problem with DPF is that people buy diesel vehicles with big engines and then use them for the school run. Short journeys dont allow the DPF to come up to regeneration temperatures. This is all mentioned in the owners manual, and it says what to do when the warning light comes on. The problem is people dont read the manual, neglect to maintain the DPF as per the instructions, and then end up blaming the DPF. Sure, there are other reasons for a clogged DPF, but they are generally caused by a failure elsewhere, like in the turbo or fuel injectors. BY FAR the biggest cause is short journeys, and then not maintaining via a forced regeneration accordingly.

The ONLY purpose of the DPF is to capture particulates in urban environments and then release them when up to temperature on the highway. If your vehicle is nearly always in an urban environment the DPF is effectively pointless, and you shouldnt be driving a diesel.

If anything, the dealer should make you sign a waiver to that effect as part of the purchase. Maybe then urbanites would stop driving diesel vehicles to look cool.