Actually, the real reason is probably that due to high fuel prices, people switched to smaller cars and fuel prices dropped again in the 80s. Once fuel prices dropped, the solar power was considered too expensive by comparison, especially in the 80s 'money is everything' culture. If you read the article, it says that even now, the power is four times the price of regular 'non-clean' power.

As for the cancer drug, I have yet to see a legitimate article claiming that it isn't being developed, just a lot of articles speculating that it might not be. I'd imagine that if the American Cancer Society, for example, didn't jump on this and fund the research, there'd be hell to pay with a lot of their donors.