You have to realize, however, that when JPMorgan and Co enter the game, it could be more problematic than good. I will also be happy for the billions in investment money they bring to the game, but they are sharp when it comes to trading for money. At that point, I hope a few coins will be stable enough that they will be separated from the investment coins and those stable coins will be used for day to day things.
I doubt that any coin (BTC included) will be stable enough not to be considered an investment coin when big banks start investing. JP Morgan's Total Equity in 2012 was more than $200,000,000,000; Bitcoin is currently worth around $10,000,000,000. If JP Morgan Chase publicly announces it is investing in Bitcoin, other banks will quickly follow. Among the big banks, there is simply too much equity; big banks will easily be able to determine the price for some time, the question is only whether they will want to. If big banks want cryptocurrencies to succeed, they will invest responsibly; if they want them to fail, they can also kill them (it would also be very hard to prove that any particular investor was responsible for a pump and dump, since they can generate multiple public addresses). Only after big money has been invested in cryptocurrencies for a while will Bitcoin achieve stability.
Remember, JP Morgan Chase just got sued for an amount comparable to the entire BTC economy; that big bank money is way beyond cryptocurrencies' line of vision.
in Bitcoin's case, I agree. I am concerned about Bitcoin's future as big investment houses come to play.
however, I am not that concerned with alt coins in general. A developer will notice the machinations of Big Whales as they come to play and design a coin that can withstand the investment plan. Notice that currently there are two VERY DIFFERENT philosophies driving the cryptocurrency surge; wanting to use a decentralized medium of exchange for goods and services and speculation to increase one's amount of legal tender. The former can by coincidence enjoy the benefits of extra US dollars/centralized currency as their crypto's rise in value, but they would rather use the currency even if it doesn't make them extra on the side. Speculators are here pure and simple for the 1000% gains that are being seen over time. They will sell it all in a heart beat and never buy a single ham sandwich if they don't want to.
The more any coin has users for the sake of using (and maybe very modest appreciation) and not for speculation, the better imho. Speculators will go where they can squeeze the most money. Let us birth a medium exchange that is design to repel those from even coming!
You are right to distinguish (some) alt coins from Bitcoin, but the problem is that precisely because the Big Whales have so much money, they don't need an "investment plan", but rather just one massive speculative attack. As far as I know, there isn't a proposed way to stop someone from shorting any currency (including cryptocurrencies).
For this reason the alt-coins are even more susceptible to manipulation since their market caps are much smaller. It doesn't matter what smaller users' intentions are, ultimately the power lies with the money. The only thing that can discourage market manipulation and profit seeking is to have a large enough market cap and hence less volatility.