Bitcoin would have been more popular and accepted by companies as a payment option if it had a stable price as they dont need to face loss due to fluctuation in price. But on the other hand, traders would not have liked bitcoin as now because they could not yield more profits due to its stable price. But for people who use bitcoin only for transactions would feel no differences if bitcoin had a stable price or not.
Given the fact that we need greater adoption, greater price stability would be required for this. But with increase in demand, price would also rise... there could be no sharp fluctuations, and that's a downside for traders, but it's something positive for users and long-term investors.