At any rate, let's take this in order. Dessies are relatively slow, but a scram or web on a Tornado will keep it in range for more than long enough to kill it. AFs/Rifters have no excuse for not being as fast as a Tornado, and can easily keep up with them if they do try to burn to range. Also I don't know if you've ever shot at a moving frigate with 1400s, but you should try it sometime for reference.
Nano ships had also goddamn better be able to keep up with them. Vagabond/Cynabal gangs will get hit a bit more, but they also put out more damage so the Tornados die faster while they're in range.
The rest of your concern seems to be that Tornados are good at disengaging, which is true. So are a lot of other fleet comps. The ability to disengage is built into all successful fleet compositions (with varying degrees of success), whether that means orbiting a gate with an afterburner and your logi until you can deaggress and jump, or nano'ing out of a bubble and warping away. As with all PvP you can theorycraft as much as you want on paper, but the performance of your fleet in space will ultimately depend on a) the quality of your pilots and b) the ability of the FC to shape the fight in your favor. Of course you can think up situations where Tornados plink away at shiptype X with impunity, but how likely are you to encounter those exact circumstances during actual combat? And once you have, how likely is it that the enemy FC just sits on his ass and doesn't try to change the parameters of the fight?
tl;dr there are counters to nearly every tactic in space combat, but you need to put pilots in space to make them work. Tornados are no exception.