to bands that use them, yes. to bands that don't use them, no...to bands that are thinking about using them or discontinuing the use of them, yes...but in a different way.
I hate crappy keyboard passages like most gothic or symphonic black metal bands use and it's what put me off keyboards overall, especially that I'm a guitar player... However lately bands like Riverside, Camel or Opeth changed my mind - I especially adore vintage keyboard sounds, like Rhodes (ahhhh...), Hammonds, Reeds or even Moogs... Maybe I'll switch to keyboards then?
Keyboards fucking ROCK!! - of course, when used right. It does create tremendous amounts of atmosphere and colour to a song, and who doesn't like a nice piano bit in there every now and again?
Bands like Anathema, Type O Negative and of course Opeth have me totally convinced that I fucking love keyboards.
if you are children of bodom, you should actually GET RID OF your keyboardist. or like that german goth band...empyrium...they got rid of their keyboardist after their second album and produced two great records in his absence.
Like everyone has already said keyboards can really add to the songs of the bands that use them correctly. Dream Theater, Opeth, Everygrey, Rush, Deep Purple use keyboards quite well.
Depends on the band. Synth can add a lot of colour to a song, or it can just sound cheesy and shit. In Opeth's case, it works very well, because it doesn't sound as though it's trying to dominate the songs; it adds an extra dimension if you like.