Is it that one party is more likely to be offended or that one party is likely to be more offensive?

What's the difference? Offense is in the mind of the offendee not the offender. Liberals in NY and SF have taken being offended to an art form I hadn't seen since old church ladies got angry when you didn't say H-E-double hokey stick.

If one side is transmit-only and never actually reads anything except keywords from the accounts they follow, and the other side is attempting to limit the amount of useless spew in their lives, that would explain the asymmetry.

I don't practice moral relativism, and that is likely outside the scope of this discussion.

My point is, it's not just a difference of opinion when a group of people promote racist, neo-Nazi views (alt-right), or peddle in conspiracy theories (Qanon).

Are we just going to ignore the significant presence of these groups on Twitter?

There's a reason why people are blocking and it's not merely disagreement. One side treats the other differently but not for the reasons being presented.

>My point is, it's not just a difference of opinion when a group of people promote racist, neo-Nazi views (alt-right), or peddle in conspiracy theories (Qanon).

    Opinion: A thought or belief about something or someone [0]

If racism and conspiracy theories aren't thoughts or beliefs about something or someone what do you think they are?

[0] https://dictionary.cambridge.org/dictionary/english/opinion

They said "it's not just a difference of opinion", not "it's not an opinion".

Self-proclaimed moderates block, unfriend and hide the least, so that would suggested left-leaning users are more likely to be offended.