From the reporting I've seen, they're not firing "at random", they're firing more or less every single new hire they can, because new hires have less protections than more established employees.
Even firing all probationary employees explicitly _for cause_ when there's no evidence of performance problems with most of them is worse than random, it opens them up to legitimate legal backlash. Have you ever worked anywhere where the last two years of hires were all just completely worthless as employees? Of course not, that's basically impossible. Eliminating these people would have been harsh but understandable if it were said to be done for simple budget reasons, because yes they indeed are in a vulnerable less protected situation, but to call them all poor performers at the same time is worse than random, it's an obvious and transparent lie.
I suspect the people in charge of the firings are under the same mistaken impression as you are, that all the probationary people are new hires who aren't yet essential. Witness the "oops, we fired the wrong people" rush to rehire.[2][3]
1 https://www.npr.org/2025/02/15/nx-s1-5298182/trumps-probatio...
2 https://www.bbc.com/news/articles/c4g3nrx1dq5o
3 https://www.nbcnews.com/politics/doge/usda-accidentally-fire...
This isn't about efficiency, money, or employees. It's about power and the consolidation thereof. They will have ransacked the VA and the American people not only gave them the keys but they cheered them on.
But as others have noted, these are not the only ones being mass fired.