In this particular mission, there isn't much they could have done other than stay in orbit. They don't have in-flight tile repair/replacement capability. The orbital mechanics were such that they couldn't reach the ISS and even if they could they didn't have the docking adaptor or EVA suits to make an open crossing.
So you have to have someone go get them. And in the meantime try to hold out with the consumables you have and hopefully not have to jettison someone out the hatch to keep the others alive. Now, who would go get them? Shuttles take a minimum of weeks to get ready for launch. How many of the Columbia crew would have to be put out through the hatch to keep the others alive waiting for rescue? NASA doesn't like to think about those kind of contingencies. The Russians? I heard they had put Buran into mothballs or maybe were trying to sell it on e-bay? Soyuz? Do they have one ready to fire? Even if they did, well, you have a problem with overcrowding. Assuming one pilot to bring up the Soyuz, would there be room for seven others? If not, who goes and who stays behind to die?
Point is, we just don't have the infrastructure or financial commitment at this stage of our spaceflight development to keep these kinds of contingencies available. Like everything, you have to do the best you can with the resources you have, doing as much with it as possible within limits. That sometimes means taking risks, which, if things go wrong, always leaves you open to Monday morning quarterbacking.
One pilot plus emergency provisions, take two(+?) back down.
And you have to know you have a serious problem in the first place. It may well be that missing tiles weren't the primary cause anyway.