You're not mad at all.
I've had lots of wp sites in the past that I used as portfolios with inhouse landers (redirecting assets to internal landing pages).
Using the WayBackMachine at archive .org I can show you an example of one of my landing pages from 2 years ago that already sold and I no longer own.
I had Lagster .com forwarding to the lander below that was monetized with zazzle products (I created a design, uploaded to zazzle, put it on beer coasters and linked to my coasters on the lander so the products were more targeted to the visitors niche they found my page for in search engines - (note: One year I sold a batch of coasters to a bar and netted $87.12 in royalties for it, later that year, someone else ordered a bulk lot of coozies for another $42.15 = A few years worth of renewals and a profit that year) - WayBackMachine archived lander on wp: https://web.archive.org/web/2022012...r-com-only-genuine-lager-drinkers-understand/
I've found that pay per, product, and service monetization strategies all work in converting traffic to dollars on inhouse landers, cutting out the middle man (e.g. parking company). Everyone monetizes differently, so do what works for you.
It should be noted, unlike parked and landing pages at 3rd parties that don't index in search very good because they are mass templated reproductions, when you use your own and create unique content like I did in the example, they do index in search and you get organic search traffic for assorted terms in addition to the redirecting typin traffic. Win win.
That means it's not just domain investors visiting, it's also consumers that may be interested in the target ad type you use (ppc, ppl, product sale, service offering, etc.) So you should start seeing a better conversion rate if done right, than you would with a 3rd party template driven lander.
In short, what you are thinking, is quite possible.
At the end of the day, what works for one may not work for another and vise versa.