This has been a topic on this forum before. Unfortunately, the decision is made and set in stone. It has nothing to do with Microsoft.

Unfortunately, technology doesn't last forever and things change from time to time, as is the case with Windows XP. There are no more security updates for the Windows XP operating system, making it an unsafe platform to use.

You can find more information about the Windows XP end of support in the Update on Firefox support for Windows XP and Vista Mozilla blog post.

Hi Scott, In addition to Wesley's answer, I get the impression that you think you are directly contacting developers or Mozilla employees. You are not. This is a community support forum. The people that answer questions here are users just like you, volunteering their time.

If you want to leave feedback for Firefox developers, go to the Help menu and select Submit Feedback.

scottflipflop said

Why are You bowing to pressure from micosoft to end support for XP the OS they ever made

Mozilla did not bow to Microsoft as Microsoft made WinXP for regular users as EOL back in April 2014. Mozilla did not bow to pressure to stop supporting WinXP and Vista when Chrome, Chromium and Opera discontinued WinXP/Vista support back in April 2016.

Firefox 53.0 and later does not support WinXP/Vista and to do some more major updates for the legacy 52 ESR would use up resources that they could use on other things.

Wesley Branton said

You can find more information about the Windows XP end of support in the Update on Firefox support for Windows XP and Vista Mozilla blog post.

That blog post was before the decision to make next ESR be based on 60.0 and not 59.0 so that meant having 52.9.0esr being the last in overlap and the EOL is Sept 5 and not June 26.