It's really not that "extreme". Many GM products from the 80's had similar setups.
For the average consumer, they don't need to know what the exact temp is - giving them more information just turns into a customer service nightmare. We see this with AccessPort's on turbo models. Give the STI owner that barely knows how to drive an STI properly a bunch of internal ECU information and watch them freak out because they see some number change and they googled it and the interwebs told them their engine was going to blow up.
GD