How did you feel about it when you first watched TNG and DS9? Did you miss the Vulcans?
Back in the day, most detractors were wondering, among other things, why Data either acted like a Vulcan or why Data was the most human-acting of the crew!

TNG already had to deal with similarities, parallels, and/or regurgitations to TOS so they had to find a new route while still feeling like Trek in the process.
I admit first I was dissapointed when after TNG in DS9 again there was no Vulcan main character.
By the time DS9 was conceived, we'd seen in TNG some Vulcan stuff but Data was already there, and the show was trying to wring out as much as possible from the new creations Cardassians and Bajorans where there was a lot more they could do and think of a lot quicker. (Then later The Dominion as a Big Bad replacement for the Borg, Garak being their version of Q, etc, repurposed archetypes
but used in new ways. As with TNG, some old character archetypes did get changed and jostled about, with new ones thrown in to build upon.)
Later all the brilliant characters in DS9 made up for it. But I still think with a Vulcan it would have been even better.
Often I read Data and Odo are similar to Spock but I don't really agree about that and they are no Vulcans in the end.
Looking forward to your opinions about it...
I'm not sure. The break from Vulcan such-n-such may have led to Tuvok being in VOY and that's when the Vulcans really get fleshed out, with a lot of thought and focus put into it. Had the Vulcans been in DS9 to this capacity, DS9 would suffer and lose focus, as would VOY - and VOY had already ditched the "two factions with irreconcilable differences and how they will get along in this uncharted area" shtick.