Many reasons for me, I don't really want one myself, but none more deadly than 'that' look from the Mrs anytime I do mention/look at one, lol.
Honestly though, don't feel I need it just yet, soon probably, but many still play on controller and I know my times/abilities aren't that far off to need one, lol. And I just don't play this one game enough in any given session. Granted, against the aliens, no hope. But the average race was all good and I always felt I was competitive, until the bumping and gaming of penalties/DR ranks etc start up. By then, didn't matter if I used blind faith, the race was gone, lol.
Do feel it's a growing gap though that should be kept to a minimum. I hope either wheel users are split away if they get significantly quicker naturally, or the developers of such equipment keep control pad users in mind and not make these things that much quicker by default just to drive up sales and cash in...
But this is modern gaming, lol. Half-ass games for AAA prices, special editions, season passes, recurring spending hooks, loot boxes, grinding, pay to win, it's all the rage. Uugh.
I know winning isn't everything, but to learn that it'll basically only happen if I spend more or lower myself to exploitative measures, completely undermines the entire purpose of the game, lol (any game really). Knowing I at rank D/C/B am to race A/S racers, OR to be against a known good driver that 'tanked' their rating and qualified a good chunk of time faster than the lower ranked racers paired up with me/us, literally just screams 'nope, not this time either pal' It's ridiculous how players do this, IMHO.
Steering wheel or not, when a game is so weak/broken it's like this frequently (or by the developers own hand with poor BoP points/penalty systems or whatever). The problems are far more troublesome than a tenth on that corner with a wheel, lol.
Anyway, simply put. If the game is done right then it just don't matter what others do and maybe folk would race rather than care what others do. Too much of that in gaming too, lol.