The story as told may be inaccurate but it wasn’t simply ‘what we had at the time’ either.
The 74 minute length resulted from Sony rejecting the Philips 60 minute 11.5cm diameter “Pinkeltje” disc size in favor of a 12cm diameter.
It’s quite possible that Sony’s Norio Ohga simply argued that the 9th symphony or various operas fitting would be enough of an advantage for the slight size increase without meaningfully decreasing portability.
Meanwhile the LP crowd was flipping sides like it was Ultima VIII (slight exaggeration). Why would it be critical for a new format to do away with multi-disc releases if the customer base has already grown accustomed to them?
For classical music it's a problem because the long track lengths mean that you'll have to flip the record over in the middle of a piece. This was enough of an annoyance that one French label in the 70s created special records just for classical music with extra tightly packed grooves that could hold close to an hour on each side (https://www.discogs.com/label/184887-Trimicron). The downside of this is that the maximum recording volume is significantly reduced so there's a lot more background noise than on a normal record.
The 74 minute length resulted from Sony rejecting the Philips 60 minute 11.5cm diameter “Pinkeltje” disc size in favor of a 12cm diameter.
It’s quite possible that Sony’s Norio Ohga simply argued that the 9th symphony or various operas fitting would be enough of an advantage for the slight size increase without meaningfully decreasing portability.