Because often that data is only available through scraping. Nobody wants to scrape, it's messy and fickle and a general pain in the backside. But sometimes the

Because often that data is only available through scraping. Nobody wants to scrape, it's messy and fickle and a general pain in the backside. But sometimes the data you need exists only in that form. If you run a website and you have a problem with scrapers, then make all that data available through an API and say what acceptable rate limits are. If cost is an issue, then charge a proportionate fee, my time writing a scraper is worth much more than paying a few dollars for an API. If you just say "No" to everything then you lose all control over the process and the only outcome will be such an arm race.