I do.
To each their own.
Edit: to expand on it:
Some fighters might like to do that, to look for openings, to look for things they can exploit.
Others trust their coach will do this and they trust the coach will traini him on it without having to go on and do it themselves.
Some other fighters might not like to see the tape on other fighters.
Most fighters are well rounded and watching a few fight doesn't mean much, since they will be training and improving, and changing their gameplan.
so as I said above, to each their own.