You are free to license your software as you wish, and I am not questioning your right to. There are three separate issues here.
>our responsibility is to choose our license terms and clearly communicate them to those who want to use the software
You are not doing this. Your website reads "Dgraph is available under an Apache v2.0 based liberal license", which is technically true but also very dishonest. Your software does not use the Apache 2.0 license, and users of it should not expect to enjoy the freedoms granted to them by the Apache 2.0 license.
>We have not changed the Apache license terms
This is not true. The Apache license explicitly grants freedoms which the following
>We have added an additional term
changes. Don't wrangle words into passable lies, you're not talking to idiots. Your wording is misleading and dishonest, which are two qualities you should be trying very hard not to associate with your brand. So far you're not doing well. No one is questioning your right to license the software as you wish. But you are not proud of your choice and are using slimy and dishonest language on your marketing material to hide your shame and trick potential users.
A separate issue is the subjective one, which is whether or not the commons clause is liberal. I think you are being dishonest here. There are widely accepted definitions for "liberal" among the open source community. The main differentiating factor of a liberal license is that it's not viral. Most people informed on this subject can then neatly and objectively file licenses into liberal and restrictive categories, with licenses like MIT, BSD, and Apache in the liberal camp, and the GPL family of licenses in the restrictive camp. However, the distinction has always been subjective, and nothing like the OSD exists. Additionally, the distinction is only ever applied in the comparison of open source licenses, of which yours is not a member. The realm of proprietary licenses masquarading as open source licenses is unexplored territory, and I'm drawing a line: no matter how restrictive a license like AGPL is, a license which is not even open source in the first place is far from liberal.
The third issue is whether or not using the Commons Clause is the right thing for Dgraph to do. In my opinion, it's a slap in the face to everyone who ever used or especially to anyone who ever contributed to Dgraph. In fact, as I was researching dgraph a bit more to see how you approached this issue, it also occurs to me that I can't find any discussion where existing Dgraph contributors were consulted on the matter of relicensing their work, which seems to me that your license change was not only distasteful and harmful to your project, but also illegal. Were all of the contributors consulted and their permission obtained to change the license? I'll certainly be consulting them if not.