Their explanation doesn’t help much and there are a few things working against them:

1. This is not the first time they have done these “hey guys check out this breakthrough!” announcements where others quickly came along and say “hey, not so fast.” (Eg Erdos) So, specifically in maths their reputation is not good.

2. They’re blurring the lines between commercial cutthroat developments and the gentlemen’s code of sorts re what’s acceptable in academic research. They were working from material non-public insights into other research, which is why they even tried to poke at this in the way they did. Doing that without collaborating first was a pretty jerk move no mater how you slice it.

3. There’s still lots of open questions about how novel the solution was and the timing here where this “test” only happened after other researchers say they fed OpenAI models at least part of the solution is a little too convenient to gloss over. OpenAI statements here to date on the matter have been rather fuzzy.

All that combined with OpenAI’s less than stellar reputation on ethics is why folks are reacting the way they are right now.