No it doesn't, it's not even close. Other companies tried to bring this same argument but failed. Some people think that the primary benefit of Open Source is having some level of access to the source code and fortunately this didn't fly, in spite of the effort of companies, such as Microsoft with their "shared source" initiatives. Open source [1] brings with it two major benefits:
1. the ability to use the software for any purpose, any field of endeavor, with no discrimination, for any business model. By your own admission, your license would be incompatible with such a contract.
2. open source can be forked, just like Monty here forked MySQL and (arguably) kept it from dying. The importance of this cannot be overstated.
But more to the point, you say you'd allow "fixes" and "local extensions", yet restrict redistribution to paying customers, but well, you clearly have boundaries in mind for derivate works, as you clearly only want to allow small improvements. Can those improvements be redistributed as source code, for the benefit of others? And if not, then clients could find themselves in a gray area. For example what happens if these clients hire contractors to provide those improvements? That's always possible with open source, just like how it is (still) possible to take your car to any repair shop. You can quickly see how this can go out of hand.
And the restriction for paying customers sounds awful - first of all, what's a "paying customer"? Do money need to exchange hands? Are trial versions permitted? What if you want an alternative business model, ads-based or whatever. Etc.
But the biggest benefit of Open Source is the right to fork. First of all, this implies that ownership over such software is achieved by anybody that wants it. And it's an important right, especially if things go wrong.
You say that you could maybe have a clause somewhere, or a promise, to make the software GPL should it become abandoned. Oh well, what is abandonment? Plus, abandonment is not the only bad thing that could happen. You could also steer the project in a direction that people don't want, you could intentionally cripple it, you could raise prices so much as to make it unfordable and when you get bored of it, you could simply sell it to another company. Notice how neither of these conditions do not classify as abandonment.
Now don't get me wrong. I have nothing against proprietary software, heck, I would be a hypocrite if I wouldn't admit to developing and making a living off of proprietary software myself.
But I see marketing attempts to redefine what Open Source means, only because Open Source is marketable, being extremely attractive at least to developers and for good reasons. And look, I get it, we need to make a living, but it's dishonest. Your product can survive and flourish as proprietary, but stop with the bullshit and call a spade a spade.