I mean, that's valid - I've been an outspoken critic of Cosmic Rewind and the amount of money that was spent on it (and how that money was used). That ride cost 3 times what's apparently budgeted for Tiana's, and Cosmic Rewind didn't even use any of it to conjure up a single Animatronic. There's some hideous misuse of funds at play on that ride.
The difference here, as we know, is that the Splash Mountain building, ride system, and show set spaces already exist and do not need to be created anew out of this budget. Since essentially the job of this transformation is to completely reinvent the theming, scenery, animatronics, and soundtrack of the ride, you would think that the brunt of the $150 Million budget would go to those. Unlike Cosmic Rewind, which is very mysteriously unambitious when it comes to theming, scenery, and even the soundscape (plugging in a ready-made Blondie song doesn't take that much work).