It is not 'hate' but not ideal either.
Take an 'average user' with money to burn. He has an Alienware Area51 Desktop with 'last gen' GPUs. How will he/she fit 2x 390x GPUs with AIB coolers? They will just opt for NV's options, or maybe not even be aware of them because their OEM only advertises upgrades that work in that case.
if they bought an A51 PC, then they are likely the type of person that likes to play games but isn't such an avid fan that it spills over into system building. in that case, marketing (Nvidia) will likely win out.
2nd example. System builder has a SLI/CF build today. They are already using their case fan slots. Now they have to choose to remove those, and increase internal temps (maybe that impacts CPU OC?) or go with the NV option without AIB coolers.
I'm certain AIBs will create fan cooled versions of the 390X. The water cooled 390x versions should help with decreasing internal PC temps since they should be placed on exhaust ports, and if someone is doing a SLI/CF, then they are more likely to be using a full tower case where there should be plenty of exhaust ports to choose from. I can see it becoming more of a problem if we're trying to also water cool the CPU or go 3-4 xfire.
I know these are not ALL examples, but when you are fighting for marketshare (and AMD IS fighting for marketshare) the last thing you want is to have your buyers jump through hoops to use your products, or limit your audience.
I'm pretty sure AMD will release a GREAT AIB cooler card. The GTX 295X was a VERY good card, but not a 'mass market' SKU. Just saying...