I agree, but sometimes these effects remasters do add a bit of icing on the cake, when they are unintrusive and congruent with the original aesthetic. For example, I thought the remaster of The Dalek Invasion of Earth was very tastefully done, such as replacing the wobbly dinner plate flying saucers with ones that looked much better but suitably 1960's.
To be honest, as a long-time Blake's 7 fan, I probably would go for a remastered version if only to forestall the groans and jeers of any uninitiated friends I show it to.