Then they have to subscribe to the mailing list, which is another set of extra steps. Some people only know the web exists and don't even know mailing lists are a thing.
Hi! If you're here, you must have found a bug. Send an email to XXX@projectpage.tld describing the bug, and we'll see to fixing it as fast as we can, and we'll alert you when we've started working on it!
You don't have to have them subscribe, necessarily.
As soon as someone thinks about reporting a bug, they’re already doing you a massive favour. Making them go away and write an email (which many people don’t often do any more) you’re already going to be testing their patience. You should be bending over backward to accept the report.
