Negative speculation will discourage people and they will stay away of the market of cryptocurrencies due to the negative news. On the other hand positive speculation in the market will encourage people and more people to take the ways straight towards this market.
This improves the mind of people and brings increase in the demand factor which further improves the value of Bitcoin and other coins.
Speculation may have a great effect on the people that have the desire to adopt bitcoin to try to earn money by trading, but for the rest of the people they are only going to adopt bitcoin once it becomes clear they can make money with it in traditional ways like creating a business that accepts bitcoin or when they see an improvement in the technology that translates in direct benefits for them, that is why even if the fees are good right now we need the LN so the issue with the fees is forever resolved.