Paper journals / magazines get read on the plane, while on the phone, etc. Electronic ones get ignored / deleted.
Alternative fogey here -- my Kindle goes with me on the plane and whatever's on it tends to be what I read. For the IETF J it's not really a fair comparison since the electronic version is full page PDFs which are hard to read on anything smaller than a notebook computer or a very large tablet.
The IEEE (most likely at vast cost) does a good job of publishing journals in multiple formats. They publish their journals in three electronic formats, EPUB, MOBI, and AZW3, as well as page image PDF that matches the printed version. Getting them onto the Kindle is about three clicks, one to download the MOBI, one to open it with the Send to Kindle program, one to tell it to send to the Kindle rather than (or in addition to) my phone.
R's, John