Here is what I think happened in the UK. Its probably incorrect and full of erros but here goes....

The strongest market was always the home organist. After import restrictions were lifted Hammond aggressively established a network of social groups called Hammond Organ Societies supported by local tuition schools where people learned to play together. This became the foundation for today's organ clubs. I think the UK was unique in that so many home organs were sold. There were shops on every high street and just about every family had a relative with an organ.

As cheaper and more attractive alternatives became available more organs sold as customers were drawn to the pretty lights, rows of tabs and low price tags; Welson, Howard, Kentucky, Viscount, Gem, Bentley, Gulbranson, Cavendish, Siel, Godwin, Panasonic, Yamaha, Kawai, Farfisa, Elka - Orla, Belton, Lowrey, Bontempi. (I could go on all night). But that was fine, because people would start of on a little organ, maybe a Welson and then after 6 months or a year would part exchange it in for a better model. The same customer would keep changing their instruments whilst they learned, getting the newest model or one with more features.

The 70s were incredible and Organ sales boomed. Then one Christmas in the early 80s, and I remember it very well as my Father managed Fox's Music Shop in Leicester, Yamaha delivered the PSR 1, 2 and 3.

That christmas, instead of people buying the little organs for £399 - £699 and then returning in January to book lessons they were buying little Yamaha keyboards for £149 or less. that in itself wasn't so bad - maybe they would part exchange it for an organ later??

It didn't happen. When people brought an organ, it was a commitment to something; a large piece of furniture that demanded attention. I reckon 90% of Yamaha PSR 1, 2 and 3 models ended up under peoples beds and in the lofts...and they are probably still there or in a landfill.

Yamaha had success afterward and established a series of music schools across the country with their own method, and for a few years the industry carried on like a fat oil tanker with no engines (through sheer momentum) due to the amount of people that were already hooked on the organ. What the industry failed to do was to keep attracting new customers for organs. Panasonic (Technics) and Yamaha became the dominant players Hammond hanging on in their but struggling to keep up with technology due to their commitment to a pure tone. Kawai for a while became very popular and Elka (then later Orla) always managed to keep head above water.

As many of the organ manufacturers disappeared, the bigger companies diversified with Digital Ensemble Pianos which dominated the market in the 90s and in to the 00s, trying to convince the same organ customers that this was they way to go, many customers became frustrated and this is where arranger keyboards came in.

There are still a reasonable number of that generation left...(these are the Tyros customers in the UK). People that are not so much players- and need their registicks and presets labeled by song name, they love to push a style maked 'miller' and instantly play a five part ensemble of Moonlight Serenade with only three fingers on the left and one on the right. They keep them for 12 months until bored of the styles and part exchange them in for the next model. They might buy a Korg or a Ketron and push the buttons for a bit, but inevitably as non players they will end up going back to their safety zone. Roland and Orla still battle on and have their own loyal customers. Hammond went back to their roots and have a nice little corner of the market shared by one or two others (KeyB for instance)
Sadly not many arranger keyboards fall into the hands of performing musicians. Its unlike the European continent where many little bars and restaurants will have a guy in the corner playing his Ketron and singing to a merry audience until the early hours of the morning. In the UK, once people have eaten their meal to the sounds of recorded Piano music they go home and are in bed by 11pm. Whilst the younger ones dance to the pre-recorded music played by a guy with a PA and mp3 player.
But...there is a smaller group of people that still go out at night and entertain - people like you guys on synthzone who put on their 'performance face' with carefully prepared playlists, on screen lyrics and vocal harmonizers. People who take a PA2x or an Audya and really appreciate it as a performance instrument. Some play with arranger modules and accordions, one or two with midi guitars and Midjays. I wish there were more of you!

Most of this is probably rubbish and I have missed huge chunks out (sincer apologies for that), but its just my take and I am going to post it before I think too much about it and start editing! in fact I am going to resist hitting the edit button!

TWD