Simplify

I read a report this morning regarding gm is having concerns with hybrid batteries leaking internally and they are calling back around 9000 vehicles from last year. Why is gm trying to reinvent the wheel in regards to hybrid vehicles? Toyota has been using the nickel-what ever battery forever and no longer owns the right to technology so why are we trying to reinvent the wheel. If I'm not mistaken, I have been wrong before, those hybrids are using a type of lithium batteries.
Also I haven't seen many advertisements for the hybrid Tahoes that make a very weak case to sell them. Shouldn't they be promoted as "if we can make a vehicle of this size this energy efficient, imagine what we can do with our smaller vehicle line-up" and show a representative pointing to a cobalt/malibu. Great advisertising for big and small vehicles in gm's line-up. Once again I could be wrong but you don't know unless you ask/comment, thanks for listening to me vent