MS SharePoint Designer為何代替FP ？

MS Office 2000/XP(2002)/2003都有FrontPage
MS Office 2000 終極版
Word 2000(.doc)
Excel 2000(.xls)
PowerPoint 2000(.ppt)
Outlook 2000(psw)
Phisher 2000 (.pub)
Access 2000(.acc)
FrontPage 2000(.htm
Accounting 2000(.002)

MS Office 2002(XP)終極版

Word 2002(XP)
Excel 2002(XP)
PowerPoint 2002(XP)
Outlook 2002(XP)
Phisher 20002(XP)
Access 2002(XP)
FrontPage 2002(XP)
Accounting 2002(XP)
TIF 2002(XP)(.TiF)
MS Office 2003終極版
Word 2003
Excel 2003
PowerPoint 2003
Outlook 2003
Phisher 20003
Access 2003
OneNote 2003(.one)
FrontPage 2003
Accounting 2003
InterPath 2003
TIF 2003
Ms Office 2007(Vista)終極版
Word 2007(Vista)(.docx)
Excel 2007(Vista)(.Xlsx)
PowerPoint 2007(Vista)(.pptx)
Outlook 2007(Vista)
Phisher 20007(Vista)
Access 2007(Vista)
OneNote 2007(Vista)(.one)
SharePoint Designer 2007(Vista)(.htm)
Accounting 2007(Vista)
InterPath 2007(Vista)
Groove 2007(Vista)
Project 2007(Vista)(.mp)
Ms Office 2010終極版

Word 2010
Excel 2010
PowerPoint 2010
OneNote 2010(.one)
Outlook 2010
Phisher 2010
Access 2010(.acclb)
SharePoint Designer 2010
InterPath 2010
Groove 2010
Project 2010
為甚麼會這樣？