What effect has Disney had on staged Musical Theatre?

Good thread and question. I don't object to Disney franchises but think that their theatre productions tend to be skin deep (perhaps with the exception of Mary Poppins, which I thought was fantastic). To me Disney is the "junk food" of theatre: evocatively engineered for mass appeal to as broad a demographic as possible with an agreed "standard recipe" that must be applied consistently. Lion King is visually attractive but gets a bit tedious after a while. I found Frozen appalling - boring, pandering to the market, with production gimmicks that are done better by other shows. Beauty and the Beast was quite impressive, but again the characterisations felt skin deep. Disney has successfully created, filled and commoditised a niche in theatre, and for that they should be congratulated. They're just not my cup of tea.

I would say that there is a "Disney sound" that vocals in Disney productions tend to have, but that has been influenced by years of Disney movies before these started to be turned into stage shows.

I know that an awful lot of work goes into making them look and sound "practically perfect", to quote from one of their hits. Once I saw the MD of a Disney production at work for a one-off performance of a number from the show, a performance they would even not be conducting personally... and I was left speechless by how strict they were on having the number performed at the same exact bpm used for the West End production (by which I mean: not a single bpm more, not a single bpm less!).

However, I have not seen loads of Disney stage musicals, the main reason being that, whilst impeccably executed from a technical viewpoint, I've generally found them to lack heart, and I have not been able to respond emotionally all that much. They always look super polished, to the point that to me they feel artificial and insincere... Sure, they're meant to depict a fantasy world, but once it's real human beings in front of me telling those stories, I should be able to see their humanity and relate to that, otherwise it's just an exercise in beautiful visuals and sounds.

Having said that - which is of course a matter of personal taste - Disney productions have done a lot in terms of providing a steady income for performers, crew, FOH staff, etc. for years and their economic success has done good to the industry, because along with the high technical standards associated with anything Disney, I understand these productions have also set the bar higher in terms of how they manage the people who make that success possible, in ways that smaller productions would never be able to afford.

There needs to be a thesis written on this!

Disney shows used to be masterpieces. Great scores, incredible sets, gorgeous costumes, large orchestras, large casts... Think the original Beauty and the Beast, Lion King or Mary Poppins. They pushed the boundaries of what a big, spectacular Broadway show could be. It also fueled up the start of the corporate musical. Shows like Wicked, Hairspray, Billy Elliot... might have not existed without Disney taking the risk and showing Broadway could be family friendly.
But after Little Mermaid flopping and a West End/touring/international market happier to pay the same price for an inferior product (my guess is since the Stage Entertainment non-replica Beauty and the Beast in 2005) and without the technical capabilities of a Broadway stage, they´ve opted to cheapen the shows a lot more while still being very satisfying products for families and the general public... not so much the frequent theatregoer who will notice those cheapenings.
Compare the original Beauty and the Beast with the last UK tour. I think it sums it up perfectly.

They've definitely had a huge impact on getting more young people into theatre (like me!). I don't think that's debatable. Other than that, everything else has already been said above.

Semantics. The original Dominion production, and even the subsequent tour were far superior to what has been slopped out since. The fact that the Lion King has clogged up the Bristol Hippodrome (our only large musicals house) for nearly a quarter of the last 2 years indicates the lazy ‘if it ain’t broke’ attitude they have displayed of late.

Seen a replica of that tour in Spain (the creatives told me it was almost 100% identical), and while it´s certainly not the original production; it´s still a very enjoyable show. The Cave of Wonders set is still mindblowing and I don´t think it is 2D backdrops, and the carpet is stunning.

He will have tempered some of the cost cutting. He likes to start high end then find ways to do it cheaper.