OP to engage with your actual question it's a matter of taste. People used to criticize (and still criticize) many mecha for just looking like stereotypical Gundams. Some people like old designs, some newer. Some people like more grounded robots and others like the big burly all out designs. Compare the mecha from Blue Gender, Dunbine, Evangelion, and Armored Core and you'll see that there's a ton of variety in designs that results from the creator's goals and personal taste. As a personal example, I love monoeye units more than Gundam eye units because I think they can allow for unique emotions. That doesn't mean the RX-178 Gundam MkII isn't a wonderful design!
A design is usually generic if it's just some grey old tincan robot that was made to be a generic robot bad guy. Even then, the Zaku itself started as a generic bad guy. In truth, it is the EFFORT put into a design that often results in its beauty.

The truth is, there will always be someone who just doesn't like what you do at all. That isn't a mark against them or you, it's just life. Likewise, there are people who will like your work.
Focus on making and enjoying robots you enjoy, and share them without fear of judgement. That is the calling of a true /m/an.