Here, in fact, I believe that this item means if I translate (after viewing their product) ...
... starting with the last half of their paragraph first (because it will make more sense) ...
People who run a CMS (website) want to be able to drag and drop cool plugins and add-ons to their site without having to learn the code. We can do this. But you want your plugins to “feel” themselves as if they were actually part of your site (rather than being imposed after reflection). Our affairs.
We are better than other guys (such as Drupal, Typo3, Mambo, Joomla), because ... Yes, they also have all these cool plugins and add-ons that will work for you (without coding) ... BUT ... Because they are "open source" and not "enterprise", you cannot rely on them! Who knows where these open source plugin developers will be in a year or two!
... this one sentence has no translation ...
Although the large community is great, the corporate approach provides a framework that you can extend to your own applications.
If I tried, it sounds something like this ...
Hat tip to open source to provide great support and development! But "enterprise" is better because you can do whatever you want to make it better (for example, you can with Microsoft Word and you can not with OpenOffice).
Since you asked “is this true,” I think the question is opinions. I would say no if you choose a good open source CMS with a vibrant community. I would say yes if you choose a sub-par tool without absolutely no community ( like this one ) ...
I’ll also note that it’s a little difficult to determine how reliable their collection of plugins is when you stay with this kind of jargon to understand this: https://www.squiz.net/resources/integration-datasheet
Again, masterful writing!