Is DMR really ham radio?

I recently found out that DMR, one of the digital systems available for ham radio, permits seamless transfer from one DMR repeater to another, like a cellphone.

So, if it is like cell phone, how come it's ham radio?

What's the challenge?

Isn't ham radio about experimentation, challenges and making friends?

Yes, I know people will say it's just one way to communicate, but so is a cellphone.

What do you think?