Institutional capital injection will bump the price, but it will also increase the volatility. Instead of a few small whales or early investors, manipulating the price, we will now see Fiat whales entering the market and pushing their weight around. These investors are purely profit driven and will withdraw at the slightest indication of bad news.

Your early investors in Bitcoin are more motivated by the technology and not just by large profits.  Yes, the institutional investors can pump the price hard, but they can dump just as easily.