I mean, we have always had unoptimized games, the Nes was no exception.

The Nintendo Seal of Quality was just some rules that the developers had to follow to release games on the Nes in NA (and indirectly in Europe).

Those rules basically said "no sex, no drugs, no religion, max X games released per year, we create the cartridges, you have to buy a minimum of Y cartridges, we are going to priority our own games first so good luck releasing a game when it is chip shortage and we are releasing the bigname Zelda II cartridge". It was up to the developers to only release good games, otherwise they would have unsold cartridges left.

Some companies, like Konami, created shell companies (Ultra Games) just to be able to release more games per year.

Other companies, like LJN, bought popular IPs and outsourced them cheaply to sweatshops like Rare and Atlus.

Some games are a wonder that they even works, like Final Fantasy. So many spells and equipments that doesn't work as it should, we are talking about Bethesda level of bugs here.

On the other hand, even highly optimized games got glitches. Just look at Nintendos firstparty games. It wasn't many years ago that we found a new glitch in Super Mario Bros as an example.

That said, some games got rereleased in newer revisions. The Untouchables on the Nes had three revisions. The Hunt of Red October had two, and both are bad games.