Still bitcoin would had strive and gained support by its supporters because then the market won't be divided, we won't had have no scams ICO that made many to lose their money. We won't have gotten the levels of successful exit scam events the industry has recorded. If it was only Bitcoin, the market would had been more safer.
Altcoins made the market centralized and gave rise to the public figures that are spoiling the name of Bitcoin since the general public associates any cryptocurency scams with Bitcoin.
It will be known shady at first but later on or when more people got involved with it, their doubts will only be removed. If there are no altcoins, I think regulations and KYC are still going to come here making Bitcoins more centralized. I don't regret that there are other cryptos because I already benefited to some of them.