What's wrong with this line of thinking is shoveling food in someone's mouth without permission is physical assault and voicing an opinion in a public space is not even close. You do not have a right not to hear ideas you don't agree with, because if such a right existed in a world with such diverse opinions, no one could ever open their mouth. Censorship of opposing ideas carries a very real and very significant cost which I believe outweighs, by orders of magnitude, any perceived benefits. The real world doesn't come with trigger warnings pasted on every surface and prefacing every human interaction, and I think neither should a university.
Obviously there are shades of gray depending on the particular speech, and we've collectively drawn a line around certain speech (call it "hate speech") which we do believe should be censored. Otherwise, the correct response to speech you don't agree with is more speech ideally in the form of reasoned and well-informed debate of the issues.
What I find the most perplexing is how, in many cases it seems like the original speech which was deemed offensive or victimizing, which typically itself was not even directed at the "victim", is answered in return with extreme prejudice and hate directly aimed at the original speaker. This can also be combined with a social media campaign to attempt to politicize the whole event and inflict maximum damage. This is why I am often confused as to who is the real victim in these cases.
The ad blocker analogy is interesting. Even blocking ads is somewhat contentious (e.g. lawsuits against DVRs with 30-second skip buttons, site owners saying their revenue stream has been decimated, etc.) and this is simply users controlling what their own devices are doing! Blocking an ad might deprive a site of revenue, but it doesn't deprive anyone else of their voice -- no one is being censored.
You say we surely allow people to shovel words into our brains... Hearing speech you don't like is one thing, but what about someone else taking their own inability to function in a diverse culture, and using it to dictate the words anyone who happens to be around them are allowed to speak? This sounds like a case where the medicine is worse than the disease.
The biggest problem with "safe spaces" is that they are not actually limited to small rooms in the student union with play-dough and elevator music, but I think a lot of people are very concerned that the intent is ultimately for the entire campus to be policed like one. And I do mean policed, because stepping afoul of the mythical safe space code of conduct is taken as a capital offense, to which you may see literal rioting in response.