Hydroponically grown plants are the same plants grown in soil, just under more ideal conditions. The question of better, then, may be better characterized as, "is a plant grown under near-perfect conditions, free of disease and environmental damage, better than one grown where it may suffer from stress, disease, and environmental damages?"
Hydroponically grown plants, whether they're vegetables destined for the dinner table, or flowers destined for your cousin's wedding bouquet, are maintained in carefully controlled conditions to promote optimum health and vigor, while minimizing damage from everything from scalding sunlight to damaging winds to bird poop on that perfect lily. Especially if you don't have a green thumb, it's better to adopt a plant in the full bloom of health than one that may already be struggling to survive.
