It has not been reprinted and is on the Pinky-Swear List. I believe it's not considered playable in Old School formats, although I don't follow them closely. And it wouldn't have a niche in Vintage or Legacy. It was last printed in Revised and new players have probably never seen it. The way things are right now, the only casual format big enough to provide a real niche for it would be EDH. I've never seen it used in EDH myself.
While it's not a perfect gauge, one test for a card's penetration in EDH is to just see how popular it looks on EDHREC. Kudzu shows up 50 decks, which is pretty close to a rock bottom of obscurity. For comparison, Raving River shows up 145 times and Aladdin's Lamp shows up 77 times, while Gray Ogre shows up 16 times. Meanwhile, old cards that are still popular have way more hits. Goblin King shows up 3,365 times, Manabarbs shows up 2,753 times, and Vesuvan Doppelganger shows up 993 times. There are, of course, confounding variables aplenty. And the timing and volume of reprints is a potential factor. But I think the numbers are clear enough showing that Kudzu sees very little play these days (and most people either don't remember it or have never seen it). In short, I think you're right.
Hm, looks like some of the decks it was showing up in for EDH were Titania decks. It's not an efficient way to kill your own lands, but it does get the job done, I suppose.