My take is that the way guitar has been used in Rock and Roll has effected the way people look at the instrument. When the Beatles first came out the press described their part in that sound was as George - Lead guitar, John - Rhythm guitar. Most every band since then, has been promoted with the same distinctions on what they do. Even though the best of them play both lead and rhythm at the same time. Hendrix is still revered for excelling at both. Beck, Johnson, a Bonamassa all come to mind in this regard.

There is no wall between lead and rhythm guitar except knowledge and practice. You simply need to decide what you want to do with that instrument you are practicing on, and go get it. If you like to play the rhythms of a song play the rhythm parts....

I think most people learn rhythm first and then go on to play lead if that interests them. Many people like to play rhythm guitar to accompany themselves singing, a task that guitar excells at. Many other people like to soar on lead lines.

Lead also usually needs somebody to cover the rhythm, so you will need other musicians (or some kind of karaoke robot) to cover this. So that is another consideration. Lead also requires a diffrent knowledge base and skill sets, beyond chording and keeping a beat.

It all comes down to where you want to go and how much you want to practice. It took me many years before I got interested in playing lead. I even described my self as a rhythm guitarist back then. Now I love playing lead as well, it just took me some time to figgure that out.