I've lived in Salt Lake City for the last five years (SLC proper, which is very "blue" and quite secular). I grew up in the Deep South. I think there's a few points worth adding to what's already here.

• There is something lots of modern people find instinctively weird or ridiculous about a religion being focused on alleged events that are very recent in time and that supposedly happened in familiar nearby places. We've come to associate more "credible" or "normal" religious belief with more exotic and ancient stories. But in terms of the theology of the LDS church in a vacuum, I think a lot of Americans would be hard pressed to put their finger on why they feel like it's categorically different than the theologies of more popular/"mainstream" religious movements.

• A lot of concern or disdain regarding the LDS faith involves: (a) doctrines and practices on the control of personal behavior, especially of sexuality and of the choices of women; and (b) the perception of a strong insider/outsider boundary being maintained. As someone who grew up in a very religious part of the country and has also lived in very secular pockets of it, I think there may be some misattribution here. Those features are also very prominent in many other flavors of popular, contemporary American Christianity. It's worth people considering how much of the perceived difference is about actual doctrine and how much is about the application of the doctrine in a more fractured vs more monolithic social landscape.
  Many of these problematic ideas were probably more popular and prominent in my hometown than they are in Utah today (which may not even be majority LDS anymore). But in most of the country, they are developed and practiced in a mosaic of different denominations and independent congregations. None of the churches have enough reach in any part of the community to keep organized track of who might be more or less a part of the in-group, since the majority of even like-minded neighbors practice in some other setting. Trying to, e.g., restrict your kids to socialization or marriage within your specific denomination is not just totally impractical but also religiously unnecessary.
  LDS congregations are also part of that mosaic in most of America, but with a difference that I see them also sharing with Catholics: they were originally built up in settings in which they were the dominant religious and social structure in the whole community. So they retain stronger links to practices and expectations that developed in such settings. Of course, plenty of people also call Catholicism a cult, but that doesn't have quite the same sting to it, does it? Everyone has watched institutional Catholicism lose its grip on both communities and individuals even when they remain more or less faithful, and everyone has seen that church sort of come to grips with that. People haven't seen that with institutional Mormonism yet, and so it's worth "average Americans" asking themselves about the similarities and differences between their feelings about LDS people today and their predecessors' feelings about Catholics in the era, say, before the 1960 elections.

• People haven't seen that with institutional Mormonism yet. But LDS church authority has now been facing both a chronic and an acute challenge.
  The chronic challenge is with the growing ranks of ex-Mormons, who now have diverse communities in which they can thrive that are now right next door to the ones they come from -- and who now have technology-driven communication and socialization practices that make it much harder to insulate the community from them or their perspectives.
  But what I really want to note is the acute challenge. Over the past 10 years, a huge number of LDS congregants have been swept up in a totally different, national movement offering to validate individual desires for power, exclusivity, and the freedom from basic moral and intellectual constraints. You can say what you will about the church's role in preparing the ground for such a thing happening, and there's plenty to say. But if you're a fan of secular liberal democracy right now, the palpable fear at LDS HQ isn't actually so different from your own fear. LDS doctrine and leadership have suddenly been transformed into a desperate and surprisingly weak moderating influence on the flock. The largely geriatric white male patriarchs have been the ones out there saying that Black Lives Matter and that the church's past overt racism has to be completely purged from people's hearts. They've been the ones pairing their traditionalist sex and gender norms with exhortations against bullying and legislative stances guided by some modicum of compassion and pragmatism. Recently they've even been getting more explicit, trying to decree that blind loyalty to a single political party is incompatible with the faith's views on participation in public life. If you've had the impression that the church runs the state here, you should get a good look at just how quickly (and gleefully!) Utah LDS Republican politicians have shrugged that church right off their backs after learning they can keep and even gain public support by the abandonment of basically every form of decency.

So if you've been concerned about some particular LDS people being in a cult, I'm not sure I'd use that word, but there's definitely a whole long-running conversation on what you have in mind. Right now, though? I'd be a lot more concerned about whether they're in a very different cult than the one you have in mind.