I don't think it's just about the ads themselves. It's about the fact that when a site is free, its users become the product, and there are all sorts of user-hostile design decisions made, which leads to all sorts of unnecessary bloat.
Think of it as the difference between a for-profit bank and a credit union. The bank exists to maximize returns for its shareholders. The credit union exists solely for benefit of its members. So the credit union isn't going to try to employ sneaky fine-print fees, because that's not what the members want.
In a similar vein, you might not care about ads and may have trained yourself to ignore them, but you might care about performance, which is sluggish because of all the cruft, or you might care about privacy, or you might care about being marketed to in more subtle ways than display ads.
Think of it as the difference between a for-profit bank and a credit union. The bank exists to maximize returns for its shareholders. The credit union exists solely for benefit of its members. So the credit union isn't going to try to employ sneaky fine-print fees, because that's not what the members want.
In a similar vein, you might not care about ads and may have trained yourself to ignore them, but you might care about performance, which is sluggish because of all the cruft, or you might care about privacy, or you might care about being marketed to in more subtle ways than display ads.