Bad software is bad software, regardless of whether it's open or closed, paid for or free.
There are many abandoned projects with obsolete products that are sometimes just bad, but often even dangerous (both open and closed source).
1. Competitive features
Often, the leading edge of functionality is in the open source segment, where you often have an open discussion regarding what to develop, and where programmers from different parts of the world compete in a cooperative way in creating and optimizing functionality etc.
Of course, in the open segment we also find much more of UNIX style modular approach, where, ideally, one program does one single thing very well, and then the user combines whatever modules he needs to get the functionality he wants. Thus, a huge functionality is distributed within the whole community, and combined to taste and needs, whereas single programs may look rather dull.
(And, you can't really charge for a program that just output text in the reverse order, can you?)
2. Insufficient user experience?
To be honest, I don't even understand this argument of yours. Of course, if no one is paying for a software product, then you can't pay much for marketing, either. This actually leads to competition around the quality of the product, rather than around marketing budget. And, if a programmer doesn't like how a program works; in case of open software, he can have a shot at the source code and contribute 15 lines; in case of closed software, his only choice is whether to use the software, or not.
Remember when Microsoft killed the efficient UI of Office 2003 for a bloated ribbon interface in Office 2007, mostly aimed at beginners. If the same change would have happened in an open product, then hundreds of volunteers would have created and maintained the "traditional" UI Microsoft didn't bother to make.
3. Dependent technology
Are you kidding?
In open software, you have the code. And if you're a bit lucky, then it will be stuffed with varying levels of hints and comments.
When it comes to closed software, the user has no clue at all. The program is a black box that may be sending encrypted emails to Bahamas behind your back. Even if the source code is well documented, you have no way of knowing it. I'm quite sure that many small closed products aren't well documented at all, since they may have been developed by one or two programmers, who never intended to show the source to anyone.
4. High maintenance cost
Well. This one is easy. For closed projects, you're in the hands of the vendor and his pricing. If you need a function no one else has, then this is going to cost a lot (if the vendor decides to do it for you), or you may be forced to go somewhere else instead.
In open software, you have cooperation around the globe. For popular products bugs and vulnerabilities are spotted and fixed by volunteers around the clock.
If your company would like to develop an add-on to an existing product, then you're welcome to do that (or ask several software developers to bid for the development). Just have in mind that some licenses will demand you give back this development to the open community.
