1. The rebuild isn't complete yet
When Stone took over as GM, he immediately inherited a firestorm, which may be why Daryl Morey stepped down. Granted, Morey said it was to spend time with his kids, who were in a gap year due to COVID, but that was almost immediately proven to be false.
Stone was taking over a Rockets team that was out of draft picks and facing tough decisions on their All-NBA backcourt of James Harden and Russell Westbrook, who were both subsequently dealt. Stone restocked the cabinet of draft picks by first dealing Robert Covington to the Portland Trail Blazers for a 2021 first-round pick, which was used on Usman Garuba.
Stone and the Rockets quickly realized the need to reload with young talent, and the Rockets finished with the second pick in the 2021 NBA Draft, which they used on Jalen Green (thanks to a little help from Lady Luck). In addition, the Rockets selected Alperen Sengun in the same draft.
In the following year, the Rockets acquired Jabari Smith Jr., Tari Eason, and TyTy Washington in the 2022 NBA Draft, each of whom has shown the ability to add an ingredient to a Rockets team that wants to compete rather quickly. If the Rockets are able to receive some assistance from Lady Luck again, they could be able to add another top talent to the core.
Then they'll be able to evaluate the team's draft selections and determine whether they hit on the picks or not. If it turns out that they've missed, it'll be time to evaluate Stone.
Then there's the free agency aspect, which the Rockets will finally be able to partake in, as the franchise will have more than $60 million at their disposal. If Stone and the Rockets wind up overpaying a second-tier player, that could have devastating ramifications for their future.
In other words, it's not yet the time to cut ties with the general manager, when the work isn't done yet, because the evaluation can't be complete until the rebuild is finished.