Can we please have a delete progress for every course?

Try suggesting it to Team Treehouse directly instead of the forums, they'll reply and tell you what they think. If you go to the Support tab and look under Learning Content, you should see this:

How do I recommend new content/new suggestions?
At this time you can email us at help@teamtreehouse.com with the subject line "Content Suggestion". 
We review all emails and make note each month of what our students are wanting to see. 
This helps shape our decisions about content and features in the near future!

No problem, Happy to help!

This is a question that gets asked regularly, and for a while there was talk about a feature being added to make this possible. But the most recent information I'm aware of about it came from staffer Jay Padzensky on 24-Mar-2017 when he said:

While I wish I was sharing good news, in the name of transparency, I'd like to share that these changes have been tabled for now. Please note that I still understand how valuable a feature this is and additional flexibility for students is still a goal. I'm sorry for any disappointment or frustration this may cause,

More recently, the staff announced the ability to reset progress for you. Here's an excerpt from a FAQ page that was posted in July 2018:

Upon request, we can reset a portion or all of your content. Please note, when resetting only a portion of one’s completed content, you are limited to 3 courses or 3 tracks or a combination of the two, as for a full account reset, this can only be done once and cannot be undone.

Please send an email to help@teamtreehouse.com and include a link to the course(s) or track(s) that you’d like to have reset.

Do update us if you hear anything new or different back from your request.