Yes, sad but true. It’s bit tough to absorb but you can a/b test to draw your own conclusions; I’m sure numbers would convince you better. Or take a look at reliable source. Microsoft, Windows, Abode and many large/popular websites used to keep sliders on front page. Now they don’t.
Not only it’s bad for SEO, it’s not good for UX as well. Adds extra js files for ‘animation/lively effects’. Sliders are big distraction. Takes 75% of front page real estate. Confuses users as to where to go next (to choose user flow).
Now I know that our front page (of the business site amrute.me ) has a slider; and that is why I’m writing this post. I’m in process of building new site for biz http://aon.works & it was tough decision to discard sliders, but yes, most likely I’m not going to have it for new site.