Do you think if BTC had a stable price which could only be altered by $0.01-0.10 it would still be as popular and as used?
In the short term, no, I don't think it would be nearly as popular. Most of the outside attention that bitcoin gets has to do with its crazy price swings. "Bitcoin up 5 bazillion percent" headlines get people's attention. Without that, I don't think there would be much interest outside of those people who are already interested in cryptocurrencies.
I agree with you. I have a couple of friends that invest In stocks and even they have a hard time to get into bitcoin.
I ask them why and mostly they says that it's only interesting when you are the first wave. They keep an eye at it for sure but not serious enough to adapt to it.
It sounds to me like your friends have some understanding of financial markets, and it sounds like they are aware of the risks that are present in investing in cryptos--even bitcoin. While I think that you really do need to be in the first wave of other cryptos to stand a good chance of making a significant profit, I think bitcoin still has waves left in it...but of course I don't know for sure.
Then they are wrong, you should explain to them that the price of bitcoin has no limit because it has limited supply but when it's becoming more popular we cannot limit the demand. It's a simple math, in fact if you will understand and you know the trend very well you could make great income here compared to stocks trading.
Limited supply makes it easier for price to increase, but you still need demand. The confidence that a lot of people have that bitcoin will keep increasing is propping up the demand right now. But if that confidence should ever be shattered, look out below.