It doesn’t really make sense if the whole point of the tournament is to promote tryharding early in the season. If that’s the goal, then reward the teams that are successful for all games not just in their group.
The emphasis on point differential has also led to some awkward moments where players or coaches are forced to “break the code”. While I think that will continue to happen I think putting more value regular season wins more will minimize those situations.
It’s only the first year, people are going to take some getting used to the point differential. People are always a little resistant to some change at first. Regular season standings are at least partly influenced by a team’s Strength of Schedule, using strictly the IST games makes sense as everyone will have played the other teams in their group. We already use Regular Season standings for playoff seeding, this IST is supposed to make these single games early in the regular season mean something more. We don’t get scenarios where one single game can affect whether your team moves on or is knocked out in the NBA often, this is also why the play-in games have been so popular IMO. It’s just another little excitement factor, what with all the variance a single regular season game could have.