Imagine a friend with a cafe, they get the opportunity to get another cafe, same area, same clientele. With the new cafe they decide to just get some franchise, a Subway type of thing. People are familiar with it and flock there in relative droves. The original 'ma and pa' cafe is therefore deemed to be not as good as a 'template'.
The other option to the franchise could have been to have gone with the 'ma and pa' offering, same deal.
But that is not all of the choices. You could actually create something new, not hold with what you have or chuck it in and go with the 'franchise'.
With website design it is very easy for people to chuck it in and go with a Themeforest effort, Shopify, Squarespace and the like.
But a lot of 'new ingredients' have came along with CSS Grid, semantic markup and much else that the themes, 'serviced websites' and the like are not up to speed with yet and show no signs of wanting to implement.
It is also possible to build out more than just a landing page from scratch in two weeks with the new tools. This involves learning instead of botching someone else's floats, divs and margin hacks. We have Cargo Cult programming and in my opinion this story is just another example of this.
I would recommend anyone else in this position to start content first, not buying a theme and then taking the photos needed to push in the theme because the boxes are there already. This is a backwards, 'design led' process and there are plenty of good reasons to go content first, then structure it properly, spend a day or two with CSS grid, then put the existing branding on there. A static HTML page is a good start, a working prototype instead of a PDF mockup.
Then, instead of the A/B testing, ask an honest person who knows a thing or two and won't bullshit you. They will ask 'why have you done that' questions which will get the content in shape. Thereafter, once you have a go at doing it you can spot what you like elsewhere and learn from it rather than cargo-cult-copy-paste it to never be confident of anything.