Thank you. It is nice explanation and agree that, from technical point of view, it is much more difficult to create a 'close to perfect' Decentralised exchange..
In my case, here problem is, investor being a not-very-technical-person, is looking at de-facto "Dex is better than Centralized". Definitely I can explain, how difficult it is to implement codes in better way. But every week or so, there has been new ICO announcing that they are coming with DEX. Many of them are not capable and just for the sake of attracting investors and create hype for their ICO sale, they anyway announce their idea. But investors are listening DEX more frequently.
Now, apart from explaining that we are not coming up DEX due to technical reasons, are there other benefits of Centralized, which can be explained ? Like, in centralized, trading fees would benefit him, as investor ? Or any more reasons to say, "We want to come with Centralized now, and DEX later" ?