Plausible, with caveats. It pretty much requires that your mages are, or at least were, the bad guys.
The fundamental difference between magic and technology in the real world is that magic is known to not exist. (I suppose if it were discovered, the word would stick, though.) In a typical fantasy world, magic is a fact of life and a part of nature, so there has to be a distinction between putting people to sleep with sand and putting people to sleep with chloroform for conflict to arise.
Traditionally, the difference is that magic is personal, disproportionately powerful and therefore undemocratic. Mages don't have a use for non-magical people, from crap-covered farmers to kings. Technology, on the other hand, works on a scale and requires the consent of the governed in some shape or form.
Fantasy settings often face existential threats from individually powerful monsters, and individually powerful mages and magic-wielders (collectively, adventurers) hold them at bay, presumably because they like the world being there. Adventurers are effectively the rock stars and gods of a setting. As in any society, there exists a system of ethics which justifies the current [im]balance of powers: it glorifies duels, individual achievement, and either hereditary nobility or allegedly fair meritocratic nobility. In this system of ethics, magic specifically and power in general is to be deserved, fought for, initiated or born into, and definitely not claimed by mobs of uneducated, undeserving rubes.
From this point of view, technology is exactly the latter. Learning the fireball spell is thought to require hard work, personal responsibility, dedication and a certain allegedly cultured mindset; meanwhile, anyone can just whip up a technological fireball in a pressure cooker. Mages don't like that.
What's [in-universe] bad about this setup is the adventurers' total unaccountability to the public. In the real world, we wish / pretend that the wielders of the biggest fireballs answer to the electorate. In a fanasy setting, even the pretense is absent: If a dragon can eat a 10k pop town and an adventurer can kill the dragon, then his or her wishes count for more than the wishes of 10k people.
Technology promises a solution to this and a complete overhaul of the power [im]balance.
Also, the rise (and abuse) of industry, given an existing magical tradition, doesn't happen overnight and doesn't have a reason to happen if the needs of the populace are met by magic. There's no need for trains and vaccines if portals and cure potions work and are available on demand. Furthermore, traditional fantasy magic would complement real-world technology: manipulating inertia and friction, superconductivity, waste disposal and of course sources and sinks of infinite energy.
So a plausible setup looks like that:
A faction of magic-wielders (of course) decided to kickstart an industrial magitech revolution. The "old guard" mystics saw the "undeserved" enpowerment as yet another existential threat to the world, something between werewolves making peasants into more werewolves and posting launch codes on 4chan. They went to war and the mystics won; the land was despoiled as a result of said war (but the mystics blame the technocrats who "forced their hand").
Mages look down on mundane humans: depending on whether magic is inherited or can be learned by anyone, the mundanes are either untermenschen or idiots/cowards who deserve their lowly station (suppose you came home after a tour fighting ISIS and heard someone complain about their selfie not getting enough likes). They also don't involve mundanes in mage-mage conflicts (because mundanes are useless).
Thus, mundane affairs are managed by the king, a mundane appointee by design: this way, mages don't have to fight for the position; a sorcerer-king would be a genuine highest office in the land, a mark of great prestige and a constant source of conflict. Because the ability to request and then dispense magical aid to the populace outweighs any possible mundane advantage, the king is fairly secure in his position and can hand it down to his children. The king's spies look for unsanctioned sources of magic, confiscate it from peasants and report particularly troublesome occurrences to the mages. And technology that could be a threat to the status quo is, of course, banned.
