They think it is too hard and say they don't want to ruin your technique
I thought I was the only pianist experiencing this. I literally cried in tears to get a piano teacher to teach me Liszt TE #1 for my mid year technical exam (the one where you have to do 2 studies plus scales etc), and it's a teacher with a masters degree with students paying $60 per hour (could be higher now)
If you don't have a teacher to teach it, the Alfred Cortot edition of Chopin. The man has mastered all Chopin etudes, has flawless technique and considered one of the greatest pianists.
I disagree. Some teachers won't teach what you want to learn, even if you pay. That's the case in my area.
When it comes to Bach, they'll teach you ANYTHING you want. Mozart, Beethoven, Haydn, Schubert Sonatas, no complaints there.
When it comes to Chopin and Liszt it rings their alarm bell.
Don't we all LOVE it when teachers refuse to teach you the pieces you want to learn?

I'm interested to know, for what reason do they refuse to?
At the time I was studying for my music degree, the common reasons teachers refuse to teach
- It's too hard (the #1 reason)
- Play your exam pieces PERFECTLY
- If you play your exam pieces well, your piano skills will "skyrocket" to new unimaginable heights
- Chopin etude is hard for you, play something easier because you can shape it and play it better.
Need I say more?
If your teacher says it's too hard for you, then LISTEN. What they say goes. I was told this by pianists and other forum members.
If you want to learn Chopin Etudes,
- look at Paul Barton's youtube videos. The man can play Chopin Etudes, and KNOWS what he's doing.
- Alfred Cortot's book
- Pay hundreds, even thousands, of $$$$ to a piano teacher who has MASTERED the entire set. There's plenty of them around.
- Figure it out yourself.
The best advice to practice Chopin Etudes -
Play it slow until they fall under your fingers