Actually there is an important difference between short leg and long leg dexters when it comes to calving problems. It isn't something many dexter breeders, especially the less than totally honest ones, want to talk about.
Short leg Dexters have an average 25% bulldog calf rate. They are a "dwarf" and the oversize head genetic risk comes with the territory. Combine this trait with a much larger breed of bull and you may be looking at serious nastiness at calving time.
That is probably the reason the first breeder who responded to your post questioned you about the short leg aspect. Had you not attacked her, you might have learned this earlier.
Also, it's just a fact of life that breeding a large bull to a small cow is inherently risky. With Jerseys, which can pretty much birth anything it may not be such a big deal. The average Dexter cow doesn't necessarily have that ability.
But crossbreeding obviously has been, can be, and is being done successfully.
It is very annoying to have your premises questioned when you post a problem, but your response was way out of line. You were rude and unnecessarily hostile. A forum is all about discussion.
Most people who are new on this board and post a question have the courtesy to be polite and grateful to the people who post replies, even if it isn't what they want to hear. Frankly it's a bit scary what you in your arrogant inexperience judge to be "enlightened".
It's your cow and how you breed her is nobody's decision- and responsibility- but yours. If your mind is made up and you just want vindication, how about putting that in your original post next time?