I would add that it is useful only for short term analysis of price dynamics, over time periods of 90 days or less. For longer term analysis of the total return on investment, it is basically useless. I'm reasonably confident that the majority of global investor holdings are held for the longer term, and that longer term total return analysis is what matters most to MS365 users, defining long term as certainly > 90 days and really > 1 year, which is the practical minimum for a long term investment.
On a more general topic, I would also suggest that the majority of MS365 subscribers (345,000,000 paid seats as of 2022) are long term subscribers, either through their place of employment, or like me, as a recent retiree, finding the subscription an essential element of ongoing productive life. While I'm a happy investor in MSFT (directly, and through numerous ETF's), it's a bit annoying that MSFT, unfortunately not unlike several other critical SaaS providers, remains largely silent and unresponsive to the thoughtfully expresses needs of their customers. Of course, I would be happiest if I heard an acknowledging reply from MSFT themselves, indicating that they would address this concern over a prescribed timeframe. Even if the answer was "We acknowledge the shortcoming, but for these reasons _____________, we will be unable to provide this improvement in the foreseeable future", I would be happier than the current silence, or in some cases, the denial of its value from various parties.
One last time, StockHistory is a certainly a nice feature, that is one bit short of being an Excellent feature for lack of an "Adjusted Price" to account for Dividends, Capital gains, and any other contributors to Total Return beyond mere price. It would great to hear anything beyond silence from an official MSFT source ... such as, we can't do this for reasons XYZ, or we're considering doing this at some point in the foreseeable future.