They make fun of the conservative or right side enough in their other content for the redditors to convince themselves its ok to enjoy Space King.
I do find it funny that these people find making jokes about "your own side" to be so unbelievably haram that the only logical explanation must be that Flashgitz unironically have the opposite politics of whoever they're making fun of (but only in this specific context and none of their prior work for the last decade+).
I don't think Don and Tom are aaaaaakkshually secret chuds or anything,
if I had to take a wild guess I get the feeling they're 99% apolitical or center-left average joes and just like what they like and dislike what they dislike, but the idea that
just because they make occasional jokes about right wingers that they must therefore be secret Vaush-tier leftoids is just terminal brain-cancer levels of stupid.
Right wingers make fun of right wingers all the time, and that goes double for centrists or politically unengaged normies.
"Errrrrrm they're making fun of you" is just a shallow attempt to politically claim a series that isn't political in nature and is just stupid fun for the sake of it, not a genuine apprecation for what Tom and Don have made. If the "no girls allowed" were actually intended as a pointed dig at people who don't like female space marines then Tom and Don wouldn't have brought up
both sides taking it seriously instead of just seeing it as a funny gag.
The entire series is supposed to evoke that vibe of playing 40k when you were like... 12. Everything about it reflects that. That's it. The show was never designed to indirectly shit on Arch Warhammer no matter how badly the redditors want it to be.
Anyway here's some hatemonger art.