I have quite a lot of rp experience, both good and bad. One of the girls I did rp with was absolutely mega good in it, but it was during time when none of us would really have much time at disposal. And when there was time, there wasn't always the lust and hunger for it. It's important to know that mood really is a thing. I've had great rp conversations that would suddenly not feel as hot anymore because there were other things around that I had to focus on. As Lee Ishler very correctly says: it can be very stressful and tiring.
Also, nothing compares to real thing. Hence why I think that rp (if it's enjoyable and both seems to enjoy each others company) should lead to at least considering meeting for real sessions. The girl I mentioned, we would definitely have met for the real deal if she wouldn't live so very far away, cause the chemistry and attraction was there. Having RP and safe conversations online during which you get to know each others desires and interests can be the perfect way to see whether that person could be a potential tickle partner.
Well that's why I do it, with the hope I can meet the right girl, and there's always the chance of meeting in person, depending on the chemistry, how far away they are, etc. It is just one more way to make a connection. I haven't met the right RP'er yet, but then I only just started doing it too. It's good experience at least. At least I'm practicing everything I'd say verbally, for when that time does come.
I think another reason why many don't say a lot in RP is they're using phones, and I get the feeling it's a lot harder for them to chat properly on them as opposed to a PC. But I don't know. I'd like to think they are getting into what I'm putting out. All the girls I met in chat I do it with are lees, so it makes sense they're no gonna say much. If there are expressive lees who RP then I just haven't met one yet. But I'm glad they let me do it, that's a good sign at least.
There's a common missconception that the tickler should do most of the talking/chatting. That's not true though. And I strongly believe it should be equal. Sadly, a lot of lees expect the lers to do most of the job during an rp, which puts a lot of pressure on the tickler. I am mostly a ticklee nowadays, although it depends on the mood (have some ler times as well), and I would never expect or require of the tickler to always be the one who makes the rp go forward in terms of setting, handling, overall description, etc.