"Better" and "worse" ARE subjective measures. Your friend's exposure to the taste of your pasta changed their subjective opinion, and that opinion became that your pasta is better than plain pasta with ketchup. That's an opinion that both of you now share - that doesn't suddenly make it a fact.
I also don't buy the whole idea of "objective criticism". Frankly I don't think such a thing can even really exist, I'm firmly in the camp that criticism is inherently subjective.
Oh boy, we're really opening this semantic can of worms aren't we?
First of all, you can criticize things objectively. For example, GSC Sandshrew's learnset via level-up.
"In GSC, Sandshrew does not learn a single Ground-type move via level-up. That means its movepool is objectively bad since it does not allow it to use its typing to its advantage offensively without one-of-a-kind TMs."
According to clear criteria and argumentation, that's an objective criticism on Sandshrew's learnset, because regardless of what one feels about it, that flaw is still a flaw.
Reviewing a whole game cannot be done without subjectivity, however, because someone chooses the topics covered in that review, most of the times the reviewer itself, and that means the criteria itself is chosen subjectively.
There is absolutely nothing wrong with that.
A review's purpose is to expose virtues and flaws, express the reviewer's opinion about something, and more importantly, allow the reader to form its own educated opinion about the subject.
On the other hand, a purely subjective review would look like this, again using the GSC Sandshrew example:
"I don't like Sandshrew's learnset."
This is obviously a simplistic and shallow comment on the subject, and will immediately be shattered as a purely subjective comment the moment the obvious reaction occurs: "Why?"
At that point, you can't elaborate on the comment without objectivity. You'll have to give some reason as to why you wouldn't like it, and you'll have to base it on, well,
reasons.
So all of us can read each other's posts and innately recognize objective and subjective points about each other's arguments. You may or may not agree with them, but to immediately dismiss the objective points is willful ignorance.
I don't even like ketchup!
Ash's Pikachu is subjectively disgusted at your post.