AirRabbit,
...IF a pilot, after passing V1, decides to reject (for whatever reason)...
I think the issue is more subtle. A
decision to reject after V1 - fine; what taking your hand off the TLs does is guard against an
unintended rejection, possibly brought about by your colleague saying "STOP!" instead of "Rotate" (has happened at least twice in my airline...) or indeed anything else that might trigger an unwanted response. IMHO we do not physically practice these sort of scenarios nearly enough to be absolutely sure what we might do under all circumstances; best not to leave it to chance, then?
If you really feel the need to do something with the TLs after V1, you still can but it will be a more deliberate action (you can still be pretty rapid if you want to).