Having said all that, this was the late 90's. Sites like this didn't even exist yet, Youtube was still almost a decade away and most people didn't have even dial-up internet access much less anyone looking for online reviews so there isn't much of a record of what that experience was like to look back on unless you were there for it.
For what it's worth, I still remember the opening of USO well before that, too which in many aspects was a disaster in its own way with attractions failing all over and them having inadequate covered queue space. A lot of people were really unhappy with MGM studios in the beginning too considering it to not be a full park compared to MK and Epcot and with basically only two major attractions that were both incredibly long but also had incredibly long waits.
In contrast, Epic is the first major park to open here in the era of social media and it has so much newness and ambition to it with tech and ops for what Universal is accustomed to. Thank goodness this is the third iteration of the Nintendo area or I feel like probably every interactive question mark block in that land would be down.