I'm pretty sure that it's a routine thing for small aircraft like Cessna's and Pipers to land at [designated] taxiways.
In the seventies, when DFW had only two main north-south runways [17R/35L, and 17L/35R], the third north-south runway [18R/36L] was the inner western taxiway! I presume that it was limited to turboprops only, since it was only 4000ft or so.
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"