I don't really mind most of the effects in early TOS as such (there's the usual matter of model scaling, and they 'could' re-imagine some of the alien planet cities that were all the same matte painting used a dozen times and reduce the re-use of some of the models used over and over as dfferent alien ships) but overall the effects really aren't entirely that bad.
Plus it would require more elaborate CGI to redo the effects to 'match' the modelwork etc in TNG, than it did for the simpler TOS.
And you have 99 extra episodes to pay for the re-mastering on!
'If the Apocalypse starts, beep me!' - Buffy Summers
'The sky's the limit.....' Jean-Luc Picard, 'All Good Things'
courtesy of Saquist