Most free web sites pay for their upkeep with ads. It has been an unwritten agreement since forever (or at least as long as there have been ads on the web) that if you consume the content, you pay the creator by looking at the ads on their site.
Consuming the content without looking at the ads is like shoplifting because you don’t like the way a store’s checkout counter works and/or the fact that they want money from you at all.
Using ads is theft (of my precious lifetime).
I call it brain time. Those fuckers are designed to stick. I really loathe everything in advertisement and if you work there you can rot in hell as far as I’m concerned.