This is one of those rare issues in which I can completely understand and relate to both sides, and for this reason I remain completely on the fence about it.
I can understand why many think it's lame. Tickling is a sensation, the act of touching somebody in a provocative way, or being touched in such a way as to cause involuntary responses. No amount of typing hahahaha will ever bring about those sensations. By it's very nature and definition, tickling is a physical thing. It's silly to even consider that tickling can happen by seeing and typing words on a computer screen.
However I can also understand why many others enjoy cyber tickling. For many, it's all about the intent or desire. Even if I'm not being tickled, there's a level of excitement in just knowing a woman WANTS to tickle me, or is thinking about tickling me, or even the simple fact that she would definitely be tickling me in real life if she could. Cyber tickling helps to demonstrate such intentions and play into the roles of both Ler and Lee.