1. Bitcoin transaction fee with using its ATM is high and many will rather consider the comfort from their mobile device than using the ATM machine for making a transaction.
Who uses ATMs for making transactions? An ATM is supposed to be used to get cash, which means that if you are using a Bitcoin ATM, you are converting your Bitcoin into your local currency, the fees might be high for that but it serves the purpose for people who might not want to go through the longer process of first using a P2P service to get money and then using a traditional ATM to get their money.
2. We can also consider the adoption and regulations over bitcoin and crypto at large by some countries as one of the major determining factors hindering the demand for the use of bitcoin ATM as some may require government approval before installation and do on, but only for countries like El-Salvador and others where Bitcoin is being supported by the government may have increasing demands on the use of bitcoin ATM.
Less adoption might be a bigger issue because, in a place where not a lot of people use or know Bitcoin, there is no point in installing a Bitcoin ATM since it wouldn't get used a lot. And, as far as I know, for a service to install a Bitcoin ATM in a country, the country doesn't specifically have to have Bitcoin as a legal tender, if it's not illegal or banned and is regulated, it can be done.