If the silver price is manipulated to the large extent that many stackers claim or believe it is, then why on earth would such stackers think that silver prices would ever go significantly higher....that would necessitate that the manipulation come to a (screeching) halt. But why would it...certainly the manipulators aren't going to somehow magically realize that they were wrong to manipulate?
One way of manipulating the price would be to wait until the silver price rises and then flood the market with silver from stockpiles. Increasing the supply and dropping the prices. But if you don't buy it back then you will eventually run out.
Why would you want to keep silver out of the hands of the people?
Harder to control wealth that you can't see. Easier for people to pass wealth on to the next generation without government interference. Harder for the gov to keep track of what benefits you should have. Harder for the gov or banks to take a cut of your savings. Hence the push towards electronic banking and a cashless society, cuts out secret savings and cash in hand jobs and tax evasion. Silver and gold provide an untrackable alternative to legal tender.
Why would 'they' want to keep the price down?
Govs want you to put your money into the legal tender, that way they can inflate away your money without you ever realising you have been robbed. If silver goes up in value people will be only too happy to have some. If the prices stagnate or rapidly collapse then people will consider it a poor investment or too much or a risk and then will avoid it.
All in all I have enough silver that if it hits rock bottom I haven't ruined my family and if it goes up I will make a decent but not life-changing amount.
The opportunity loss only assumes I would have invested my $ elsewhere, which based on my previous history would have been Star Wars Figures, Lego Sets, Sealed boardgames and Magic the Gathering Cards, so not really much of a loss, even though all of those have made more money than Silver recently.