Nothing wrong with simple.
A basic truth in brewing is, brew what you like, and the hell with everyone else. If your tastes run to a small selection of styles, the you are blessed indeed.
For those who are more prolific in their brewing, the chance of variety, and being true to style, will lend one to be more discriminating in their yeast choices. I know many home brewers make their one "go to" beer most often, and that's fine, but Ive got an 8 keg keggerator to feed. That requires a pipeline aproach to brewing. What good is it to have 5 kegs of APA, and 3 kegs of Stout on tap? Each tap should be differing in some degree.
Therefore I have no less than 8 yeasts on my ranch, that are in constant rotation. When a successful beer is packaged, the yeast is washed and a selected portion is separated, labeled, and put in cold storage awaiting its next use.
This is a copy of my brew log for this calendar year ( sorry, my handwriting is crap). I have brewed 14 times and used a total of 8 different yeasts, with the Guinness on 28 Apr. being the only one purchased new this year.
I guess my point is that I don't need to conform to three yeasts. I have my own supply, and brother, life is good.