Matter of opinion, My 1st keyboard had 49 keys as did the 2nd & 3rd. Just from a playing point of view it only frustrated me. They're OK for MIDI sequencing & programing but not for most playing. Why impose that limit unless you have no choice?! My 1st real synth had 76 keys. Currently using 61 and don't like that either. 3 big advantages to 49 or less is cheaper buying & shipping, portability, and footprint.
In some cases you can remap the keys but some virtual instruments use 5 to 7 octaves for operation so there's no room left to do that if you want the advantage of using all of them - a must if you're playing live or recording.
Others say "why not just learn to play the guitar?" The same could be asked of any other instrument for which a plethora of virtual examples exist:
1. It takes years to learn.
2. It takes even more years to play good enough to be heard or recorded.
3. I'm not in show business so it doesn't matter if it doesn't sound real or professional.
4. Real guitars & stomp boxes cost too much.
5. Real guitars & stomp boxes take up too much room.
6. The neighbors will complain about the noise and the landlord will evict me.
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7 It's my choice how I do this, right?