Yep. I am one of those people who both bought and built just to mod Oblivion and Morrowind.
Played Oblivion and Morrowind on console for years and never really felt the need for mods. Then when Skyrim came out, I played Skyrim for about a year on console until I got bored with it and frustrated with many aspects of the game I did not care for but could not change on console. Got so frustrated with vanilla Skyrim that I went back to Oblivion. But after getting frustrated with what I saw as the shortcommings of Skyrim, I had a harder time overcoming the shortcommings of Oblivion.
Finally decided to buy a gaming laptop, solely to mod Oblivion. This was a big step because of my very limited computer knowledge at the time and how intimidating it sounded to mod Oblivion with all the weird jargon modders use, not to mention the various and somewhat wierdly named utilities, like Wrye Bash and BAIN installer, TES4 LODgen, etc. I did not know a mesh from a texture, much less what a LOD was, and everything I read about how to mod a game just sounded so incomprehensible that it took many many hours of study over a period of months before I even felt competent to start modding a game.
Then, after spending several months getting a stable load order set up for moderately heavily modded Oblivion, I decided to take a run at modded Morrowind. Since I had a knowledge base from learning to mod Oblivion, getting a stable load order set up for Morrowind only took a matter of weeks, rather than months, although there are quite a few significant differences between Morrowind and Oblivion due to the somewhat similar but distinctly different utilities (Wrye Mash, mlox, TES3cmd, TESTool, MCP, MGE XE, Exe.opt) vs (Wrye Bash, BOSS, TES4Edit, TES4Lodgen, TES4ll, OBSE, OSR).
Then I wanted even better performance, so I built a gaming desktop solely to mod Oblivion and Morrowind. Again, I had only very limited computer knowledge before buying that laptop, but learning to mod Oblivion and Morrowind gave me the confidence and skills I needed to learn to build a PC from scratch. It was much simpler and easier to build a PC than to mod those games.
I have not bothered to mod Skyrim yet, and I still play it a little on console, but I am still frustrated by all the things I dislike about the vanilla game (and there is a very long list of stuff I would "fix"). For that reason, I don't play much Skyrim these days. Someday when I have a bunch of free time, I will spend the time to mod the heck out of Skyrim. I always tend to overbuild things, and the desktop I built is no exception. It can certainly handle anything a heavily modified Skyrim could throw at it.