You bother because it can be hard to find a lab that gives you reproducible and reliable results... At a price you can afford.
For example, I can't find anybody to do a mericloning run on a couple of my nicer minicatts (awarded ones). To rephrase, I found one lab, but it will cost me $10,000 to do it. I don't have that kind of capital. I could do it myself, if I had the time, for far cheaper.
For flasking of seed, I have a couple of local people who do that for me, but neither is really up to my standards. And I don't blame them, they have real jobs too and it can be hard to keep up with flasking work. Again, if I did it myself I would at least be guaranteed that any mistakes were my own damn fault...
I have done flasking work in the past (in graduate school, when I had time and equipment). It isn't that difficult. Of course it helps that I spent 5 years of my life doing mammalian tissue culture for 10 hours a day... But I think anybody can learn how to do it. At least for seed flasking and replating, that is pretty easy. And I think homemade equipment is fine for that purpose. You can get some good ideas for building flasking cabinets and home flasking techniques at Aaron Hicks' site (http://members.cox.net/ahicks51/osp/)
. Someday relatively soon I will set up a lab in my basement. When my basement is finished... After the plants are repotted, maybe. *grin*