What do you mean by "scientific"? It seems like you mean "propositional".
"Ice cream is nice" is not nonsensical. It falls into a category of utterances that actually say something about the speaker rather than the thing indicated. "Nice" is shorthand for "deemed by the speaker to be of high value". It can definitely be true or false. However, due to the clever formulation, if I disagree with you, and say "Ice cream is not nice," I'm not really disagreeing with you, but rather stating something about myself.
That's not to say that there's no such thing as nonsense statements. But, to the extent that you're really doing philosophy and not just making word salad, philosophy has no place for nonsense.
I'd point out that some of Popper's criticism of what science is and what sciences isn't was based on a response to Marxism, which was wondrously flexible enough to handle any sort of new information without changing its underlying beliefs.
"Ice cream is nice" is not nonsensical. It falls into a category of utterances that actually say something about the speaker rather than the thing indicated. "Nice" is shorthand for "deemed by the speaker to be of high value". It can definitely be true or false. However, due to the clever formulation, if I disagree with you, and say "Ice cream is not nice," I'm not really disagreeing with you, but rather stating something about myself.
That's not to say that there's no such thing as nonsense statements. But, to the extent that you're really doing philosophy and not just making word salad, philosophy has no place for nonsense.