There are many reasons brewers choose all grain over extract brewing. The main reason brewers switch to all grain is because it gives the brewer more control over the final product. Another reason to brew all grain is because it is generally about 40% cheaper to brew than malt extract beers.
Some brewers make a big deal about it, others don’t, but the clarity of my beer as of late has been a big deal. I think it is just a natural progression in brewing education. Relatively speaking, concern over clarity only became relevant when we stopped drinking out of wooden, stone, and porcelain mugs.