The best motivation for completing a project is a deadline.
If I don't really have one, I make one up; "this will be great for somebody's gift next Christmas or my guestroom for when in-laws come for the holiday".
How I accomplish this and still satisfy my itch for a new project too is this:
---I make the big WIP a priority, and allowing plenty of time, stay committed to the deadline.
---After awhile, if I'm craving starting a new project, I choose a small one with no deadline although I may have an idea for it's use in the far future.
---I keep the big WIP the priority. When I'm really losing interest, I use the smaller one as a reward for time spent on the big one.
---I do not start another small project until the first small one is done.
---I keep the big project the priority.
---By the time my larger WIP is finally done... and on time... I also have 1-many smaller ones done.
---If the smaller projects were BOM, then it's time to make a big sampler and that becomes the big priority.
I have met every deadline for special occasions or personal enjoyment by starting way in advance. By the time the bigger WIP is done, I also have finished smaller gifts that are separates or make up a set ie pillows, or the parts of a larger one ie blocks for a sampler quilt.
Having the one large project and alternating with small ones during the process works for me. I suggest you select one of your 25 incomplete projects and alternate with a new but smaller one, never starting another large or small one until you finished the first ones. Eventually, your 25 will get done and you will have many smaller ones all done too. And you will have a plan that will keep you from having too many UFOs lying around frustrating you.
Quilting is supposed to be fun, not frustrating or embarrassing.
You want to show up to the special occasion (birthday, wedding, anniversary, graduation, baby shower, holiday) then at the party, like everybody else, present your quilt gift, not a note about it. People, including you and your own house should be getting use out of your quilting. And, like somebody before me said, an unfinished quilt top will not keep anyone warm.
Having said all that, I also have a completely different suggestion.
If you absolutely just love making the pieced tops, pay somebody else to do the rest, per your fabric selections and sizings. Don't be embarrassed about it, just acknowledge that it is your strength and preference. Your family and friends will still love them and admire the work you did do. Ask around, maybe somebody you know hates the piecing part and loves to do the quilting and binding. You could "pay" her by giving her a finished project now and then.