Software in Software Boutique doesn't have any comment at all

Is this normal? The Ubuntu Gnome Software has a lot of comments...very helpful...

Yes, that is normal.

Thanks for the answer. I understand if they create a comment section then it may looks bad since Ubuntu Mate user base is not massive. Developers may want to think about how to improve the comments from Ubuntu Gnome...

Is there another software center that I can install with software comments?

Yo can install the Gnome Software Center by either:

Going to Software Boutique and then going to More Software and clicking on Software

Or via the command line using apt install gnome-software

Thanks. I can use both Software Boutique and Gnome Software Center in Ubuntu Mate without any issue?

Yes, Software Boutique currently is a curated collection of tried & tested, recommended software. It is expected to visit More Software to explore the rest of the Ubuntu catalogue.

Software Boutique 2.0 will add support for comments as well as being able to explore the Ubuntu archives (and snaps) without needing another software manager. These ideas have been on the backburner for a year or two. We should have it ready by 20.04 LTS or earlier.