Just saw your contributing guidelines:
https://github.com/jakartaee/data/blob/f7fbd095443c43d9c3a62ed75ac196f405ac8c1d/CONTRIBUTING.adoc#developer-certificate-of-origin---dco

Feel free to close for this small change, probably not worth it. You can also replace the inverted boolean literal yourself...
In case I ever create another PR, I will follow your rules...

p.s.: when an existing thing out in the wild is later considered for standardization things could be challenged more.
JPA is so full of flaws that have been blindly taken over from hibernate.
Jakarta data is on the same way with the "magic query from method name" approach adopted from spring-data.

And having findAll by default is also a huge anti-pattern:

In real life projects this often leads to catastrophic disasters when newbie developers find this method and start using it without thinking what may happen if you have millions of records.

All just my very personal opinion - feel free to ignore ;)

@hohwille thanks for your feedback.

Just saw your contributing guidelines:
https://github.com/jakartaee/data/blob/f7fbd095443c43d9c3a62ed75ac196f405ac8c1d/CONTRIBUTING.adoc#developer-certificate-of-origin---dco

This is standard process for all Jakarta EE projects under Eclipse. If you are able to, I'd encourage you to sign the Eclipse Contributor Agreement so that we can merge your PR.

Jakarta data is on the same way with the "magic query from method name" approach

The Query by Method Name does offer some compatibility with existing solutions, but looking forward to the next version, we are planning some alternative patterns (such as #857 and #829).

And having findAll by default is also a huge anti-pattern

I remember there was a review of BasicRepository methods prior to version 1.0, due to which several were omitted. I don't recall why findAll made it through. While it could be useful in some specific scenarios, in general, it is as you said, and anti-pattern. I would have rather seen users opt in to it than get it by default.