People are entitled to their opinions of course, but personally think there is a place for live samples and backing instrumentation... BUT, like all aspects of music, it should be done tastefully!
My old band used samples and backing instrumentation live because there are real logistical issues that limited our instrumentation live... Reality:
1. not all stages can support eight band members, and an eight person payroll for an originals project is stretched at best.
2. it would be entirely unprofessional in some circumstances to need 45 minutes to set up and sound check.
3. our "sound" included electronic elements like 808 hits and percussion elements in addition to synth and orchestral parts. Yes, we would have loved to always have a 40ft stage and afford four keyboard players, but that is not always realistic.
All four members of that project are proficient at multiple instruments, so you can kiss off if you think that we were not musicians. We wrote, recorded, and orchestrated all of the samples, and had it tight with our live instrumentation. That is an art in and of itself... It requires a lot of time learning equipment and getting everything tuned up... "Lazy"... Hardly! We poured countless hours into making a seamless, high energy, professional performance that left our audiences with jaws rightfully dropped! ... And we could be on and off the stage in 15 minutes... That is all you have when you are a local opening for larger acts.
I agree when it is not done tastefully it is really wonky, just like a poorly placed guitar solo, or a poorly written drum fill... But some of these opinions are really ignorant about the entire idea of sampling.
Like a lot of aspects of music, there is a place for it! Hell, most of the naysayers on here probably wouldn't have the first clue as how to pull it off anyway.
One of my more recent projects is a one man band where I play live looped guitar, bass, keys, omni chord, theremin, vocals, live lighting controls, and live DJ elements.... But I guess I'm just a hack with backing tracks...