I posted this answer long ago, but it seems time to resurect it !

I've been performing as a solo artist since WAY before arrangers or midi were introduced. I played straight piano(Rhodes) first, then added Moog bass(left hand) then a drum machine and finally, when midi was introduced ... I layered a synth with a second sound for my right hand "color" sounds while keeping a dedicated keyboard for piano parts.
This lasted till the arrangers finally put good sounding drum machines in the keyboards. after that ... I slimmed down to just one keyboard, but still played all the bass and piano parts live to the rhythm machine looped patterns.
At first - the idea of using an "oom paa" (arranger) backing was unacceptable to me, but slowly, the patterns got better and better .... so I caved and used a few at a time. I spaced them out and used the arranger sparingly.

With the advent of midi ...many players started using sequences to add the hands that they could not provide, and give them a competitive edge with guys like me - that could get a party dancing with just MY hands. Well ................ the midi sounds got better and better, and pretty soon, the accepted "norm" in the trenches (clubs and parties) included at least at SOME level ... midi backing tracks. This was all taking place at the same time that the "K" word was being introduced from Japan. The K-Jays were getting about $300 or more per show to just emcee the night. Made me sad ... but I still worked the same schedule. 5 and 6 night a week and lots of afternoon parties and studio sessions. DJ's only hurt the bad musicians, or bad business people.

If you were a singer or guitarist in the 70's and 80's working clubs and eeking out a living ..... it became almost impossible as the 90's drew near. Bands were downsized to fit the diminishing budgets in the rooms and rising insurance rates due to DUI laws kept the clubs from paying a lot for live music. The returns just weren't there. At least at a "K" show .... people came in. Granted - they act like morons, but they DO fill the seats.

My point is this:

Many fine singers, drummers, guitarists etc. that used to work a lot were out of work all of a sudden due to downsizing. What do you do if you are the piano player in a 5 piece band? You play piano right? Do you play everyone else's parts too? NO.
I see nothing wrong with playing YOUR instrument to the capacity you are able, along with accompaniments by either live musicians, midi tracks or arranger patterns.

I see no difference in the validity of the performance.

My people come to see me make a show.
I make parties.
I set tempos.
I pick WHAT to do and WHEN.
I get paid to keep the action rolling.
I sometimes use arranger patterns, sometimes manual bass and drums, sometimes midi sequences, and sometimes I use custom made audio tracks from my studio with backing vocals and extra instruments. All these tools provide me with a means to an end. They allow me to express my creative talents to make a show.
Pushing fill-ins and selecting variations takes as much time, energy and expertise as it does to play creative, two fisted parts on a kb while a sequence plays the rest of the band's parts. Just like we ALL used to do when we had live playing members in the band. Remember bands?????

I miss playing funky clav parts to disco and R&B tunes. It's much more authentic and energetic if I sequence the backing tracks and play my ass off on the D6 or the Rhodes. Even when I play bass ... I can manage to get the groove happenin' with just those 2 hands, but it's harder to make a full sound because SOMETHING is always left out.

I like arrangers. I like sequences. I like simple piano chords. In short ......

I

Like

Music.

I like playing it, and I like the people to like LISTENING and DANCING to it.
I find that mostly - senior audiences are the quickest to accept a "canned" arrangement of a song, while the younger crowds definitely respond to the sequences more. I am STILL working the keys and the crowd ... but in a different way.

My basic rule of thumb is this:

If it WORKS .... keep doing it.

So many times at weddings you'll hear 4 or 5 fast, modern tunes in a row and only a handful of barefoot, beer-drinking girls are dancing. Then a slow standard comes on and the floor FILLS up! Does the entertainer follow that with another slow one? Usually no. They change gears again and lose MOST of the dance floor.
Idiot behavior. Give 'em what they like.

Today's music is getting more and more "signature" specific with certain riffs and catch phrases that make it impossible for an arranger pattern to do justice to the song. If your crowd is over 40 (55 really) .... you have a shot at acceptance using arranger patterns, but the younger people see it as "hokey" and sophmorish.
I tend to agree. In low volume settings, especially. Sequences are lame when played softly. They need the energy from the movement of air, since there is NO one sending the energy into the performance at THAT specific moment.

In many cases - I'd rather play a left hand bass line and right hand chords to a drum beat than use a generic, overused pattern that sounds like every other player that owns a PA80. I like that intimate, small combo sound that only manual bass can provide. There is much more energy and "groove" when the piano and bass are in sync. For bigger sound - the sequence is the winner. The arranger fits somewher in between the two. (easy fellas ....... it's just MY views)

To summarize ....... there is NOTHING fake about using backing patterns, tracks, sequences, or whatever - as long as YOU are in control of the performance and you are playing YOUR part along with it. If you want to be a "front person" - that's OK too ... just don't fake it on dead keys. Get out in front and sing to the clients. They are VERY used to that concept.
Playing arrangers is a shortcut to a good sound, but it should not be a DESTINATION to aspire to. Use these tools to help you learn how to put it all together .... then go do it ! The important thing is energy. That comes from hard work Learn the parts !