A large tank does not automatically equal a stressed ball python.
In caparison to a smaller tank, a large tank is harder to maintain temperatures, humidity, and the sense of security.
Temperature, humidity, and the sense of security can all be provided properly with the proper equipment and care. It is essentially a the same as a smaller tank, but on a larger scale, which is more difficult and more expensive; therefore less popular.
In the wild, ball pythons live in small abandoned rodent burrows, but they have the choice to move from one hiding place to another as they like. This a reason why some owners wish to provide their snake with a large enclosure.
Just because a ball python does really well is a small enclosures, that does not mean, it has to be in a small one. There are plenty of experienced owners on the site who can tell you that they have large enclosures with no problems. At the end of the day, every ball python and every owner is different, there are general rules for the keeping of ball pythons, but they are not set in concrete.
It is really discouraging when new owners sign on to this site, and people tell them to get ride of some of the things they own or just bought. Instead you can make more reasonable and kind suggestions, in this case: A large enclosure will be harder to maintain, but that does not mean it cannot be done.