My motto in life is : you don't have to be a baker to judge the quality of the bread. (And I'm french, bread is religion here)
Comics are made for readers, normal folks not artsy people here to determine what brush you used and how long it took you to draw a page.
And if you think about it, all those youtubers who make films or video games reviews aren't directors or programmers... They just comment on a media they love and use everyday.
But I know what you're saying, in the presentation of our channel, we mentioned that we were far from being professionals and that it was just our opinions, blablabla.
Also, we take care to review comics we really love so that we have more positive things to say than negative (it helps on the snob thingy).
For this reason, I would also advice not doing requested reviews, a lot of these feel a bit dishonest because most of the time, the reviewer is trying really hard to find something nice to say about a comic they're not really interested in and it shows (which makes the review less interesting and the reader/viewer less interested...)