MAGA and “just conservative” are not the same.
Self-labeling as MAGA is denoting full cult of personality and fealty to Trump. Add the online-ness element, plus the small size of Lemmy in general, and you’re concentrating that presence into a toxic sludge that seeps into the rest of the fediverse a la 4chan/Xhitter trolls.
“MAGA” is not going to change their minds on anything, nor are they looking to meaningfully change ours. MAGA does not argue in good faith, or based on rationality or policy. Red-hatters enter non-red-hat spaces for the purposes of intimidation, feeling superior, and sowing discord. Then they pat each other on the back for “owning the libs” and continue the cycle.
It’s perfectly reasonable to not want to federate with relentless trolling and become a Nazi bar by means of association.