If I'm YC and I have invested in a company, I'm going to step in and give a bit of coaching in a situation like this. Especially when the solution is completely obvious and the core action required (deleting the account, sending a quick apology) would be minimal.
The entire premise of participating in YC is to learn from other founders about how to build a successful startup. You're saying that YC doesn't have any reason to try and help founders do better at running their companies?
It's up to the founders to reach out and try to figure out how to solve the problem. If they don't do that YC isn't going to perform an audit or hold a bunch of seminars or something.
TBH most of this is basic competence. YC can't ensure that all of the companies are competent in all aspects.
Remember, pg has defended a YC company's sleazy tactics for bundling unwanted software in installers (including disguising the choice to install them as an ordinary EULA acceptance scheme, which he whitewashed as confirming that they wanted to install the software) and even that didn't do them any real damage.
I expect pg to defend profitable sociopathic behavior; but this destroys value. If he's not providing any coaching, it's probably because he already wrote the entire team down to zero and thus doesn't want to invest 14 seconds in a text message telling them to 'fix this ASAP'
He also defended AirBnBs founders when they were publicly blaming-the-victim: customer whose house had been trashed by meth heads after renting it out on AirBnB.
Eventually the company seemed to hire a crisis consultant and started acting better.
But in the early days the founders were being extremely douchy and PG wrote an article that I was astounded to receive, defending the douchiness.
That was the point that I started to think YC isn't better than the average level of Silicon Valley.
BTW, many YC companies engage in fake traction tactics sometimes ones that cross the line into dishonesty-- for example AirBnBs "we'll spam people listing their places on craigslist while pretending to be someone else" marketing scheme.