I carry them on trailers like they are cartons of eggs. I maintain them like they'd explode the moment they passed some scheduled maintenance item. I keep them clean and always touch up the paint on scratched areas to prevent rust. However, I buy my tractors to work. If they won't take being pushed at the very limit of their abilities each and every time I use them, I don't need them. I pay good money for top quality equipment and I expect that equipment to hold up when I need it most. Perhaps this is one of the reasons I dislike most every hand tool and power tool that Harbor Freight sells. I have always been a relatively large and powerful guy and still have some powerlifting records standing from the mid 80's at local gyms and one where I attended college. When I grab hold of a wrench that is attached to a stuck bolt, something is going to move! With cheap tools it is generally the tool shattering.
I view tractors the same way. I could save thousands by buying inexpensive off brand tractors. It's just that I've looked at these sort of tractors and have seen where they save money. I generally do not agree with where they've cut corners to get their costs down. Believe me, I've looked at plenty! Although I want to own quality equipment, bragging rights mean absolutely nothing to me. Just look at my signature. Do I look like a guy who is bragging about what I own?? (and, yes, I do actually own what is listed in my signature...that 8 hp 19" push mower is a beast!!) Based on the forum in which you posted this question, I'd venture to say that as long as you don't abuse, just use to it's maximum potential, your tractor; you'll be fine. Kubota makes a fine tractor and I've seen quite a few survive what I consider abuse for many years without breaking. Just realize that there is a difference between hard use and abuse. It may be a fine line, but there is a difference.