Why the facination with integrated amps?


I don’t get it. Is it the manufacturers spotting a trend with the tail wagging the dog or does a significant market segment truly prefer the idea of an integrated?
Pros;
Less space
One less set of IC’s
In theory-one less chassis/case to pay for
Shorter signal paths possible
Can combine transformer/cap function
Cons;
Power supply interference/spuriae
Reduced Flexibility-can’t switch amp or preamp as easily or go to monoblocs
Less resonance control
Long history of lesser performance per measurements and long-term subjective listening
Less resale value if it turns out to be a fad
Less liklihood of an extremely high performing active preamp

I freely admit I am a skeptic. The industry-like so many others-looks for new market niches to move product. 
FWIW, the only integrateds I myself would care to audition would be from Esoteric and Luxman who have a long history of designing no-compromise (low-compromise) high-end integrateds. 

128x128fsonicsmith
Since there's been much discussion of the higher end...

Homage to the 'reasonable' end of the what's possible (purely as an example):

Outlaw Audio RR2160 Stereo Receiver USD $849 List.

MM/MC Phono; HD/FM/AM Tuner; Internet Radio; USB-B input; USB-A Input; Equalizer loop; Bass Management; Tone Control; Subwoofer Output; Headphone Output; Mini-jack Input; Accessory 5V DC Power; Digital Inputs; Pre-Out; Volume Control; Remote Control; etc. etc. etc.

If one does not require the gain provided by the pre-amp section of an integrated and most separate pre-amps, a power amp with a built-in passive pre-amp (control of volume, switching, etc.) is an attractive alternative to a conventional integrated (which in many cases have a power amp section compromised in the interest of meeting a retail price point).

There are some of that kind of product available, and I could provide the name of one tube amp designer/builder who will I believe install a passive pre-amp in one of his amps if you so desire (he approves of the concept). I could, but have been reprimanded for "pimping" for him and his products. Can't have that, so you’ll have to figure it out for yourselves. Hint: He was for years located in beautiful Santa Barbara, but has relocated to the Berkeley/Oakland area in N. California (not without its’ own charms).

Yeah, if you think you need high quality active preamp better go with separates, I guess. Would Diablo's power amp section equal or outperform any separate power amp in most cases within this price range ? That's an interesting question. Theoretically, one can add separate active preamp to Gryphon, let's say tube preamp, if they electrically match well. Adding separate tube pieces to Diablo, phono and active preamp, and see what happens would be true audiophile experimentation.
fsonicsmith
excellent query with corresponding Pros and Cons accordingly.I believe that it is fair to report that in 2019, the Integrated Amp, has become a strong competitor to Separates. No doubt that some audio manufacturers build Reference quality products currently. Add a little advanced technology by way of a DAC or server/streamer capabilities, one can be musically rewarded. Last year, I had the aural pleasure of auditioning the Anthem STR integrated amp. This year, so far, I have had  the aural pleasure of auditioning an AYRE AX-5 Twenty integrated amp. Both are very musical, the AYRE, moreso as reflected in its price.  I am going to take a second demo with the AYRE. I never thought I would ever consider an integrated amp?
Happy Listening!