Rubbish. The limiting factor is expense. DDR3, SATA and PCI-e have been used for years. Before that, DDR2 was used for years.
CPU support is limited by BIOS support and price/performance tradeoff. Four years on there will be new chips, whether the expense is worth it is a different matter.
Disk controller? Either buy a new controller card and run it at full speed, or if using an ancient system, an adapter. There are adapters to fit SATA/SSDs in everything from IDE (very cheap) to SCA (wincingly expensive, but if you want to put one in your 90s Unix workstation..)
Graphics card? Endlessly upgradeable, within the constraints of your PSU providing enough power.
Biting the hand that feeds IT
