Why the facination with integrated amps?

The easy answer is value.  I just went through a complete upgrade of my system and the need to combine surround processing for TV/Movies along with my desire to get great 2 channel performance led me to the integrated amp world.  I couldn't touch the performance I'm getting out of the McIntosh MA8900 integrated without spending probably two to three times as much on quality separates.  That and the fact that this unit integrates (no pun intended) nicely into the surround system made it an easy choice (see my comments under the thread "New McIntosh amp build quality" - have an issue that they are addressing).

Oh, then there's the W.A.F. which was a fairly important consideration.  The Mac doesn't eat tons of space or look like an industrial relic from the 1800's.  

To each their own, but I think in today's audio market, integrated amps have a lot to offer at every budget level.

@fsonicsmith "Resonance control" WTF is that? Also, how on earth would a few inches/feet shorter "signal path" make any difference at audio frequencies? And what is combining transformer/cap function? That is some electrical engineering people don't learn in school, so you might enlighten us. :)) 

The price of good cables (ic and pc) plus good equipment support (space issue) is enough to go for an integrated. 

I can think of many reasons.  Cost, Space, Convenience etc.    Sure an integrated includes tradeoffs.  One power supply for all sections is a compromise that may have audible consequences.   Lack of flexibility outside of basic features may inhibit future upgrades.   But the real question to me is how much more do you have to spend to meaningfully improve sonic performance ?    Lets say you purchased an integrated for $5k after comparison with $5k in separates (pre- media streamer/DAC - amp), and determined that you could not hear much if any difference.   At what point would you hear enough of a difference to offset the increase in cost ?   $7.5k $10K ?    For many, cost is a consideration.   For most, integrateds are so good that it is only at the margins where improvements can be heard.  And for many outside of the suburban/rural US, space -IS- is a consideration.   A single elegant box is a much cleaner aesthetic solution when space is at a premium.     I use an integrated in my computer system (MF A3.2), and a former TOTL HT receiver in my family room (Marantz SR7009), but separates in my main system (tube, with 2 TT).

A minimal word answer ... dollars, space and ultimate listening use