I don't agree with the gatekeeping of the take from a literal point of view, but rather I think that the sentiment of "It is reactionary to support exploitation and oppression, and it is hypocritical to claim that you oppose it while still continuing to support it" that leaks from it is spot on 
Also, I gotta love how someone posted two separate comments within a minute of each other just to articulate a very short point of this take being "ableist." That's 100% indicative of seething.
I also love (this time using this word unironically) that she's a fellow black vegan communist who is sick of non-vegan leftist bullshit.
tbh it makes it seem like bait for these kinds of replies
Regardless of framing, the notion that leftism and carnism are, in any way, compatible is a false one. Also, even if phrased in a kinder, less absolute manner, it seems rather naïve for one to expect that carnistic leftists would not find a take that points out the discrepancy between leftism and carnism to be upsetting. Doing so seems to be inadvertently validating this notion that people have an issue with vegans being "rude" or how they "approach" spreading their ideas. This isn't true. Rather, they have an issue with vegans being principled and unapologetic regardless if they are rude or kind in the process, and they are uncomfortable with the ideas themselves.