Was E/I meant to kill network cartoons?

Maybe that's a bit of an extreme accusation to make but either way, lets first take things back to see how we ultimately got here. Back in 1969 we got Hot Wheels on ABC, which was the first 30 minute animated TV series based on a toy-line. To make a long story short, this inevitably didn't go over so well with both parents and the FCC, who naturally viewed the show as little more than a half-hour toy commercial.

Regulations were soon put into place to ensure that nothing like this would ever happen again. And by 1974, rules were made so that no television show could be based strictly on merchandise (especially toys aimed at children). This however didn't stop popular shows from spawning toys afterwards.

By the early '80s under the Ronald Reagan administration, the government passed legislation relaxing this regulation and every cartoon (He-Man, G.I. Joe, and Transformers were pretty much the big three) was suddenly just as they feared in 1969: A half-hour commercial for toys. To put things into proper perspective, even the Rubik Cube by 1983, had its own weekly animated series.

Some of them tried to appease wary parents and such by adding 30 second "morals" to the ends of episodes (e.g. G.I. Joe's "Knowing is half the battle!" segments), but by 1990, the FCC realized what a horrible mistake that whole experiment had been and started trying to get back to how things had been prior. It should be noted that major related factor involved regulations on advertising in and of itself, and the programs were seen as a loophole to get around those rules as well as make money off elementary kids.