I've had plenty of dirt issues with film. Ever get a grain of sand stuck in the felt that put a nice scratch in several rolls of film before you found the bugger? Oh, yeah. That's a good way to screw up an entire day's worth of shooting.
Then, there's the whole issue of cleaning, cleaning, cleaning film before printing. If you just let some lab deal with the processing and printing, then you'd not know about this one. However, all of us that did all our own processing know all about it. Heck, I'm going through old film shots these days, scanning them into digital, so I'm *still* cleaning film!
Personally, I'm much happier with the state of affairs when it comes to cleaning the digital sensors. But, then, I've never seen it as much of an issue. I'm used to working on electronic devices, so I have a very nice binocular zoom microscope (actually, two. One is a Leica and the other is a Nikon) on a boom stand with a polarized ringlight. I can see the dirt very well and just remove it.
But, that's just me.
As an aside, why is it that professional shooters will go out and spend tens of thousand of dollars on high-end digital camera gear, yet won't spend that extra thousand or so on tools to allow them to deal with the cleaning of the sensors? I bought that Nikon SMZ-2B stereo microscope with light off of eBay for $750, (my Leica Stereo Zoom 5 was even cheaper) and it makes cleaning the sensor a walk in the park. It's also great for removing splinters from fingers.
Now, as for the complexity of the modern cameras, I'd prefer to revert back to dedicated controls as opposed to multi-function controls that change what they do depending on which button you're pressing.
This applies to film cameras as well as digital. Think FM3a vs. F6.
Obviously, there has to be some form of menu control system for the digital section, but the shooting section can be dials and knobs and levers easily enough. Take a look at the Leica DMR scheme for a good example of this.
All that said, there's plenty of room for all forms of digital cameras in the marketplace. One doesn't have to stick with a DSLR just as one doesn't have to stick with a P&S. Lots of tools for lots of folks. One of them should fit the bill, I'd think.
Yes, in time we'll probably have a universal camera that only needs one lens, regardless. If you look at the high-end television cameras these days (like the ones that cover major sporting events), you'll see that they go from very wide angle to extreme telephoto with a single zoom lens. Of course, the lens is the size of a 600mm f4 tele, but it does the job with a HD (which is 2 MP, btw) sensor very, very well.
The other course of action would be to use a much higher resolution sensor, and then pull the old digital zoom, aka crop, scheme. This is much cheaper than using the super-zoom optical scheme. My problem is that once I have all the resolution on the sensor, I want to maximize it for every shot, so I change lenses all the time, and just deal with the sensor cleaning.