First, I'm no fan of the busses, and I really like the monorail. It's like an attraction in itself for me, mostly for nostalgia. I also remember WDW when you could go almost anywhere and never have to ride on a bus. It was really cool, a much more immersive experience. So if it's just a yes/no question, I would be for more monorails.
But, you have to recognize the reality of the situation, and realize that money spent somewhere is money that won't be spent somewhere else. Big bucks spent on the monorail system are bucks that can't be spent elsewhere. And I think that in order to answer the question of whether I support expansion of the system, I have to ask what the consequences would be. More monorails = fewer new attractions.
In regard to complexity, I've spent many hours working turnstiles at TTC and EPCOT, and the idea of transferring at TTC confused lots of people. More monorail lines = more transfers = more guest confusion. Most people can handle waiting for a bus that has their destination on the front. It's simple. The experience is nowhere near as "magical" as the monorail, but it's not confusing.
And I like the idea of a different form of transit. I recently rode the DART system in Dallas, and it's pretty cool. I kept thinking that this sort of light rail would be great at WDW, and would probably be cheaper in most spots than monorail beams, since you aren't trying to build a heavy concrete and steel beamway on swampland. But with another transporation system, you get into the issue of transfers. Now that I think about it, transfers also take time, to get off one vehicle, find the right ramp, wait for the next vehicle to arrive, and load. More transfers = less time in the parks.
Finally, a story. A couple of years back we stayed at the Contemporary, in the now-doomed North Garden Wing. What a great location. One morning we were headed to the MK, and it's so close and it was such a pretty morning, we decided to take the 10 minute walk. On our way there, we were passed by a monorail guy, walking along the path to the MK. He had the costume, and the radio that leads wear. When I said, "Why are you walking?" he replied, "Fastest way to get there." And when I thought about it, he was right. The walk was probably twice as fast as the resorts monorail. Moral of the story: Even if you like the monorail, it's not always the answer.