Actually, it is not just the Eurocrats. In fact they should be second in line for the spoilsport title.
The death knell of the Defender sounded the moment Blair and Co made into a "car" out of a commercial vehicle while keeping crew cab trucks as commercials. It has been selling less and less from that point onwards.
The 2020 emission regs are just the final nail in the coffin. The remainder of the coffin has been put together by Brown and Osbourne for many years.
If it was tax-deductible as a capital asset the same way you can do with an L200, Denver, Navarra, etc it would have sold enough for Tata to try to find a way around the regs. After all, everyone who is building pickups have managed to get something lined up for that date somehow.