How many consumers use mobile? Have you ever visited website only to find that it doesn't work when you really need it to? You get annoyed and click off the site. Not good UI for the visitor and a lost customer for the site owner.
If you were that site owner, you'd be pretty steamed especially when you know it was not your fault but the fault of the web developer not doing their job properly.
In this instance it's the specifically the fault of the author of Final Tiles Gallery. He has sold a product that claims to work on mobile device...erm actually, Diego ( representing the product/author) , you have not been transparent.
My gallery ( your product) does NOT work on mobile device and I have submitted numerous support tickets, also PAID for support and you have not bothered to reply with a suitable fix after 3 months of waiting!
You see, the author has misold the product claiming it has features that works on mobile - BUT FAILED TO WARN that it may not work on certain wordpress themes.
So if you are considering buying this product , please be warned and do not expect any customer service- even if you have paid for it.