Perhaps, but...
This is what's really getting on my t**s at times. All this "they have stolen this from us" (even if sometimes true) is basically just digital device evolution. Because as you've said, ultimately there's a necessity of I/Os, switches, possibly an EXP pedal and a display of some sorts.
Given some brief research, the first to release such a "complete" unit have been Digitech with their RP-1 (no expression pedal, though, but that's something people not generally agree upon as a necessity). That was 92/93. Then there's been the GT-5 (96), followed by things such as the Korg ToneWorks AX1G (99), Digitech RP200 and what not.
These pretty much were the "role models" for that format, with the GT-5 likely being the first that was actually used in a more or less professional context by some players (in fact, a guy I know, killer player, has stocked 4-5 by now, so he's got spares until the end of his life), maybe this worked out so well because the drives and such were analog (the amps obviously weren't). I should actually take mine out one day and see how well it holds up in case I'd run it through a better cab sim...
Anyhow, the first complete floor modeler made by Line 6 only came out in 03, so that's a decade afrer the RP-1 and still 7 years after the GT-5.
Apart from the improved sonic qualities, pretty much any others were just UI improvements on the same theme. And as said, it's a logical evolution anyway.
