I generally like to think about this from opposite direction: miners and bitcoin investors are incentivised for bitcoin to be used and for the price to go up.

Why miners? Because their main source of income is not the transaction fee, but basecoin, the guaranteed bitcoin payout for each mined block.

Due to Bitcoin being such a huge amount of money, unethical players do anything to lure people in, including MLM-style marketing, artificially inflating volume traded, and overplaying coin stats (like market cap). Then there's also media / influencers who, without second thought, introduce inexperienced people to investing in high-volatility assets.