I disagree. When I first started offering feed (RSS) subscriptions on my blogs, I had a link to a page on my website at CoolAdz.com that defined feed, explained how to use RSS, detailed where to get a feed reader, and the discussed the difference between subscribing by RSS and by email.
What I have found is that many bloggers subscribe by RSS. They do not read all the feeds, they just search for certain keywords, author or blog name. They glance at the entries and read the ones that interest them. The feeds may stay in their reader and they may refer to them later.
An email subscription services sends an email to your readers' email inbox every time you updates your blog. Unless your readers want more email, change your email delivery schedule to arrive on a certain day of the week. Of course, your readers may still visit your blog in the meantime, but a weekly email/newsletter will them updated without crowing their email inbox.
You may notice I have a subscribe by Bloglines badge in addition to the other options (above). Bloglines was one of the first blog readers and some page ranking programs use subscriptions through Bloglines to value blogs, so I leave it.
If you would like to have a better understanding of RSS, blog feeds and subscriptions, please visit my website CoolAdz.com. If you have any questions after reading this post and that web page, please feel free to leave a question here and I will help you if I can.