With due respect, I think that excuse is getting as old as the read option.
The Raiders were put together in 1960 as an AFL team that was nothing until it merged with the NFL in 1966. So they are maybe a late second generation team as I was 10 years old in '66.
Success will build a fan base quicker and without having to wait for generations, simple as that. The generational excuse is used when the franchise sucks. When the franchise exceeds expectations, that success is credited with building the fanbase. Can't have the convenience of excuses for either.
Sustained success in the NFL is quite possibly the most difficult thing to accomplish in the sports world. The Patriots are a fine example of sustained success but have lost the superbowl the last two times they were in it. That franchise was considered snake bit untill drew bledsoe went down and that gangley kid from Michigan stepped in and changed history. The panthers until this 4 year skid were near the top of the nfc in wins second only to Philadelphia. In 17 years we have had 4 playoff appearances, 3 NFC championship games, 1 nfc championship victory and a super bowl appearance. aside from only making the playoffs 4 times out of 17 years those other accomplishments are pretty good.
I was a fan as soon as Mr Richardson announced Charlotte was getting a team in 93. The fans are here and they are growing in number. I believe a mixture of time and success build the great franchises. Success will come with our new QB. Might as well start being a fan now.