In defense of out-of-tune pianos
Play them anyway.

Concert pianist, teacher and teacher-trainer here:
Play your out-of-tune piano until you can get it tuned. Play your whole heart out.
Yes, I know about the ear training and the tone sensibility and all that.
Yes, I understand the importance of having a properly working instrument.
Hear me out:
If you have a piano and you're not playing it because it is out of tune or a couple of keys don't work, behold!
I had to reschedule my piano tuning because my mom got ill on the same day as the appointment. This is how it sounds before tuning.
E-flat 4 won't play because of my cat. Carter had his way with the hammer. That needs to be fixed.
G4 used to play but now it plays simultaneously with G#4, also due to the cat. Fun.
Those three notes are smack in the middle of the keyboard. I need them.
But I will still play the piano, with gusto.
I will work around those notes, using a different mode or octave or whatever.
I will play along with the radio too. It means I must use my ability to hear and adjust, to transpose and compensate, instead of reading the chords and trusting them. (Sometimes the lead sheets are wrong so, really, we all should be listening anyway).
Play your out-of-tune piano until you can get it tuned. Play your whole heart out.
Secret: Most musicians can't even tell at first when a soloist is out of tune if they play with their whole heart. And the musicians who can tell usually have perfect pitch (and it'll be torture for them and I'm sorry about that).
Play. Play with the instrument you have, as best as you can, until you can improve the circumstances.
We teach this to everyone.
Lessons? Curriculum? Teacher training? We do that, and with zeal. Lessons@ThePianoInstructor.net