Regarding gamedays specifically: I've found that many company leaders don't embrace them because culturally they're not really aligned to the idea that incidents and outages aren't 100% preventable.
It's a mistake to think of the incident management muscle as one you'd like exercised as little as possible when in reality it's something that should be in top form because doing so comes with all kinds of downstream values for the company (a positive culture towards resiliency, openness, team building, honesty about technical risk, etc).
Sadly this can be a difficult mindset to break out of especially if you come from a company mired in "don't tell the exec unless it's so bad they'll find out themselves anyway."
Relatedly, the desire to drop the incident count to zero discourages recordkeeping of "near-miss" incidents, which generally deserve to have the same learning process (postmortem, followup action items, etc) associated with them as the outcomes of major incidents and game days.
Hopefully this outdated attitude continues to die off.
If you're just getting started with incident response or are interested in the space, I highly recommend:
- For basic practices: Google's SRE chapters on incident management [2]
- For the history of why we prepare for incidents and how we learn from them effectively: Sidney Dekker's Field Guide to Understanding Human Error [3]
[2] https://sre.google/sre-book/managing-incidents/
[3] https://www.amazon.com/Field-Guide-Understanding-Human-Error...