So are you saying is it hypocritical for a Witness to be wealthy?
The whole "keeping your eye simple" thing is actually about what you as a Witness are seen to be doing. This is especially true if you are male and could be used within the congregation.
So... if you are educated, wealthy, run a business, live in a big house or whatever then it's all about how much you ministry you do, how your "spirituality" is perceived, what you do to be a proactive and reliable appointed man, how your wife and kids are perceived (note that perception and reality often differ), how useful you and/or business is to WTS goals, how well your face fits with the BoE, how wealthy the area and congregation you are in is and so on. The more boxes you tick the less attention is paid to your wealth.
On the other hand, if you are wealthy and couldn't care less about the meetings, ministry and so on then immediately it is your wealth that becomes equated with materialism and used as a stick to beat your perceived lack of spirituality with.
I agree that it's not uncommon for those with less wealth to look at those with it and find fault. Sometimes it's well deserved, other times I think it is simple jealousy. A so called "simple eye" and lack of materialism are not limited to those without wealth, it crosses all segments of society. Hypocrisy amongst prominent elders is also not restricted to the more wealthy ones.