A CLA in itself is not necessarily bad, but it depends greatly of what the license is and what it says about future intentions.

There had been many instances of copyright folders using the CLA as a means to go proprietary so the community is understandably wary about it today.

If the current license is permanent and non-revokable like one of the well-known ones (GPL or MIT to name the most) then even if they change it later the code up to that point would remain under that license and can be forked freely.

The issue in that case is not losing the code, it's that the copyright holder has a long term plan where they benefit from community help for a while then take the product close source to monetize it, which is regarded as a dick move.

IMO there are benefits to any project that uses a FOSS license even if temporarily if you can fork it afterwards. And let's not forget that you can also fork it during.