I'm not sure that pot grown tomatoes crap out sooner than those grown in the ground. My next door neighbor has her plants in the ground at pretty much the same location I have mine in pots. My plants have as long a season as hers, but I do get fewer tomatoes, throughout the entire season, and mine tend to be a little smaller in size. We generally grow the same varieties, so that isn't much of a factor.
Different tomato varieties do mature at different times. Some are early yielding, others mature weeks later. It may be that the types of tomatoes that people tend to grow in pots, like the patio tomatoes, just don't have as long a producing season, so it appears that pot grown tomatoes crap out sooner than those in the ground. That's one reason I don't bother with the patio tomatoes. I'd rather put the effort into regular varieties, use stakes and tomato cages, and get longer lasting plants, better tasting tomatoes, and a longer season from my pots. If you only have space for a patio tomato, they will still be much better than anything you can get at a supermarket, and they do take a little less work.
The bigger the pot, the better the tomato plant will thrive, in all respects, not just the length of the producing season. I do think the ability of the pot to retain water is a major factor. Smaller pots retain moisture for shorter periods of time, particularly in very hot weather. You can water the pot in the morning, but, by mid afternoon, the pot has dried out and the plants are starting to droop. This constant drying out is not good for growth or tomato production, and the problem gets worse in late July and August, just when many varieties of tomatoes are reaching maturity, because it is hotter at that time. With larger pots you can water once, or twice, a day, and maintain more even growing conditions for the fruit. That's essential because the water content of a tomato is fairly high--if the plant isn't getting enough water, the water isn't available for the fruit. Without sufficient, consistent moisture the stalks also tend to become more spindly and problems can begin to appear on the tomatoes. The watering problem doesn't affect tomatoes grown in the ground nearly as much as it affects those grown in pots.
I"ve also found that fertilizing pot grown tomatoes is somewhat tricky. If you use too frequent applications of a water soluble fertilizer, you get rapid growth, but too much growth is diverted into the leaves and stalks and you may wind up with fewer tomatoes. I try to enrich the pot soil with a good amount of organic matter before I put the plants in the pots and then I cut down on the amount of additional water soluble fertilizer I use after that.
Growing tomatoes in pots is not my preference, I'd much rather grow them in the ground. But I don't have full sun in an area where I could do that. So, I have resorted to growing them in pots, which I have in my driveway, where I do have full sun a good part of the day. It's not ideal, but it's the best solution I've been able to work out. A fully ripe tomato, right off the vine, with a little salt, is possibly my very favorite food. I refuse to forgo that treat. So I don't care if it looks silly to be growing tomatoes in your driveway, although my neighbors seem to get a kick out of it. I even inspired my next door neighbor's little vegetable patch in the front of her house. Where there's a will, there's a way.
msolga, most of the time I get a monster yield from the cherry tomatoes, and the plants are huge. I think they are sensational in pots. More folks should try growing them.
Now I can't wait until the danger of frost passes, so I can get started with my tomatoes....