I think the immediate reaction from people invested into Bitcoin would be negative, when they hear that some new Alt coin or "Blockchain" based technology was launched. You immediately think that money will flow away from Bitcoin to these Alt coins and Bitcoin will lose investors.
Could a new coin attract new investors to the whole Crypto currency scene, that would not have invested, if it was not for this coin?
Let's say for instance "Mc Donald's" launch a new Alt coin, called "McCoin" and Billions of people starts to buy and sell these coins. What would the natural spinoff of this be? I think "increased awareness" of Crypto Currencies. A percentage of these people might start to trade other Alt coins or Bitcoin as a result of this.
Do you think this is Good or Bad for Bitcoin, when this happens?
With the overwhelming development of new coins every day, it turns out that some of these coins are just copy paste of others and some are eventually being abandoned by the developers and just exist in the market for speculation purposes. With thousands of coins created, there are some that has a real world purpose while some are just all idea even if there is a successful ICO as they wasn't able to develop a product yet.
Even if only half of those coins or even a quarter of it is viable and use by the people for its actual use, it is good for bitcoin as for me since it will help with the exposure of cryptocurrencies. If someone benefits from those coins, he would promote it to his family and friends and then others would learn about cryptocurrency. There would be a bad impression though when someone bought a coin and he was dumped on.