Nope. That's a bit of a myth/ fantasy I think some of us like to tell ourselves. But for myself when I see soft looking skin/feet... that tells me that they are not only well taken of... but, theres no rough skin to be a barrier to the nerves endings. Now... for me it's a huge turn off to see rough feet anyway ... but that does't mean they are not ticklish.
More than anything sometimes I think excessive tanning might decrease ticklishness but... if anything that would take years to accomplish if such a thing were to occur over time. But, I don't know.
Ultimately, I think its in our minds that we can judge someone's ticklishness just by looking at their skin. We're just more acutely aware of skin itself and how vulnerable it is to us.
I guess soft skin with less calluses in general is usually more ticklish but I think ticklishness occurs more in the brain than anywhere else. I've seen people with baby soft skin that are not ticklish at all and people with rougher skin be ridiculously ticklish so I think it varies from person to person.