Yes, that is why we had been sitting on them for so long. Never really wanted to do adsense since it would be advertising our competitors. Never wanted to create a bunch of thin content product pages linking to our sites (we actually did do one 6-8 years ago and it did tremendous, but not so much in the last 3-4 years since Google Panda). Have no desire to sell the domains either.
So you believe we are doing the correct thing by just sitting on them and waiting to do an entire site centered on those specific niches? That's what we feel, but it seems we are also squandering opportunity. (we've been sitting on these for 12-15 years now). Just wondering what others think as well.