This just seems a complete 180 from the Psychonauts review in terms of what Yahtzee's looking at.
The complaints are legitimate. The game didn't exactly live up to its potential and suffered from somewhat of a lack of cohesion. It was quite short and some things weren't explained too well (the Hornthrower in particular, though that isn't anything too important in the game). I do not think that it's quite as good as Psychonauts.
The thing that seems off to me, though, is how Yahtzee really brushed aside the actual fun of the game. The imagery, story, characters, world, soundtrack (licensed and original), the humor and the overall style that makes Tim Schafer games great. In the Psychonauts review, he talked about how he could let certain handling issues slide for an artistic and original game. Even if they aren't put together as well as in other games of his, though, it's worth addressing the unique elements of this game, though, in more than one line. Those parts cannot be understated as they are critical to the Schafer experience.
That, and his RTS friend isn't playing it right. I'm not just hopping on the 'agree with Tim Schafer' band wagon, I really think that you miss so much by just making units and sending them to another location. Sure, from an overall RTS perspective, it is really giant tug of war that doesn't involve much besides getting units from one end to the other. That isn't the main aspect of the strategy, though. How you support your units and use them individually changes it from a linear RTS struggle to a series of dynamic battles that you need to control and join from two different perspectives. If you don't help your units, take advantage of your unique solos, make use of the various powerful double team attacks or fend off the enemy from doing the same then you'll lose pretty easily. I also think that the two elements seem to break each other up when they would normally get dull. You don't have to keep mashing buttons in the fray, nor do you have to sit and just deal with the logistics. I also think that this is the most playable console RTS I've seen yet.