Since it's the ERA of Lowman and many disdain 18 man parties to kill anything, RDM is viewed as something of a relic by the community.
It does have its uses, as a healer and nuker but sadly it is outclassed by BLM, WHM and SCH in those respects. Then again for exp pt's in abyssea people will take RDM without hesitation for Cures and Azure lights.
Now don't lose heart at being relegated to a 2nd string Healer/Nuker. Many more of the newer NM's are vulnerable to Para II, Slow II and Addle. Not all of them are, but enough to justify the luxury of taking a RDM if the person organizing a particular fight so wishes.
Moreover between Bio II, Drain, Aspir, Dispel and T3/ T4 nukes RDM can help trigger a number of
Yellow weaknesses to help speed up fights. It can cover all but it can cover more than a few. Splitting up spell casts only helps speed up the whole fight as you're not stuck waiting on one mage to cycle through all spells.
In the end it's really all about who you play with and the niche you carve out for yourself. While much is changed look at all as an opportunity to do new things. If anything RDM's now can cast off the shackles of haste/ refresh bitchery, so enjoy the freedom from being insta-spammed by requests to keep those cycles up the moment they go down.
As is, welcome back!
Remember to enjoy yourself!
cheers!