You've solved the problem of accuracy, but you've now introduced a huge recall problem. Your query will never find a page advertising 'the best shirts without stripes', as it contains the word 'stripes'.

To be useful, Google must solve natural language problems. You can't solve natural language problems by using formal language in sine bits of the problem, at least not until we have a full Chomsky-style understanding of the whole of human language.

English is fine, googling for "stripeless shirt" works well enough. The question "shirt without stripes" is begging us to ask is whether we might want to reevaluate projections of imminent AI takeover.

Just being silly here but the same issue happens if you do the search in Spanish :)

https://www.google.cl/search?q=polera+sin+rayas

It does, if you're running a search engine for a general audience. the `-` operator is useful, but it's almost an admission of defeat: what most users want is to be able to describe what they're looking for in reasonable english and get relevant results back. Having `-` for advanced users is useful, but it's not friendly to the majority of users.