You can maybe get a patent for the process, but can you get a patent for the resulting lifeform or its individual genes? My understanding is that you can not, but if that's wrong I'd love to be corrected.
I agree that gene patents and whether to use GMO manufacturing are two different issues, but given that all of the GMO companies seem to be grabbing patents on their products, not buying GMO products seems like a good way to not support these practices. Especially since we already have GMO labeling in some places, whereas patent-information markings are very unlikely to ever be implemented.
Yes, you can get a patent. There are even organisations that aspire to patent organic plant variants that obviously aren't GMO. [0]
>given that all of the GMO companies seem to be grabbing patents on their products
No, not all are. First of all, not all developers of GMO technology are even companies - they may be universities or government agencies, for instance [1]. The widespread and misguided opposition to GMO technology works to the benefit for large companies (like Monsanto), though, because they have the resources to hire enough lawyers to manage the process where it matters.
Secondly, there's nothing "grabbing" about filing for patents or equivalent IPRs for plant variants; it's what you need to do to protect your variant even when you plan to release it into public domain (so that a malicious party would not claim them).
[0] https://www.geneticliteracyproject.org/2015/08/07/challengin...
(It's often GMO in the sense "let's take a bunch of seeds, expose them to radiation and carcinogens, and experiment with whatever comes out.)
In some countries (e.g. mine), these rights are not called "patent" but are not substantially different from what they are where the name is patent.