Is this indicative of a hardware problem on my computer? It really never crashes, it's been perfectly stable generally, and other programs work fine. I ran some memory tests and disk scans just to be sure, and I tried switching the bitcoin data directory to an alternate drive and nothing has improved.
Exactly, it is a hardware problem. Bitcoin Core is really well optimized and stresses the machine very close to the theoretical limits. In particular "disc scan" isn't a good test, what you need is a "disk read-modify-write" test.
Also, if your home PC is running Windows the unfortunate standard advice does apply: online antivirus programs are frequent culprits of corruption of databases, especially since a while back when some joker pushed a virus signatures into the Bitcoin blockchain.
For your comparison: I have a very old kitchen computer, original Athlon 64 Clawhammer from 2003 running Windows XP SP1. It still runs fine 4 coin wallets {Bitcoin,Litecoin}*{mainnet,testnet} simultaneously.
Here's another thread from another user who had "mostly stable" computer:
https://bitcointalk.org/index.php?topic=1106669.0so you could commiserate together.