Actually, you can read the content of a post even if it has a direct, external link. You just have to click on the "Responses" link at the far right. But still, it's very annoying that it's necessary to pay such careful attention to the "external link" icon and then click the "Responses" link if you want to avoid visiting spammy sites. You should always be able to click on the title because it should always take you into the post instead of directly to some external site.