Kodak USED TO make d-slr bodies that used the Nikon F-mount. FujiFilm USED TO make d-slr's that used the Nikon F-mount. Kodak USED TO make a d-slr that used Canon EF mount. This was back when these cameras ranged in prices from a low of about $2,999.95 up to $7,899.95.
Kodak's early DCS-720 and DCS-760 were full-frame d-slr's that were VERY expensive, in the early 2000's; the Kodak 14n was a Nikon F-mount d-slr that had a then industry-leading 14 megapixel sensor, and it was followed by the Kodak SLRn and SLRc models (Nikon and Canon variants). FujiFIlm first had the FinePIX S1 Pro, a 3>6MP model way back in the early days of d-slr's before Canon had anything on the market, and the Nikon D1 was current; Fuji followed with the S2 Pro, S3 Pro, and then the S5 Pro, which was built on a modified Nikon D200 body. As I recall, SIGMA also made a d-slr that used Canon EF mount, but it was a failure.
ALL OF THE ABOVE cameras were basically, of limited acceptance and limited commercial success. The most widely accepted and successful was the Fuji S2 Pro, which was a good shooter, but it was a two-system camera, which required batteries for the "digital side" and separate batteries for the "camera" side. This camera was $2400 when introduced. The huge successes came with the breakthrough camera models from Canon, and Nikon. The Digital Rebel, the EOS 10D, the Nikon D1 and D1h, and the Nikon D100 and later the Nikon D70 were models that had HUGE success.
The m4/3 and the 4/3 lens mount cameras have had extremely low sales numbers. Fuji and Olympus have recently let some sales numbers out on their compact mirrorless sales numbers; we're talking in the neighborhood of 500,000 to 604,000 cameras per year, from Fuji and Oly. There is absolutely ZERO profit potential for Canon or Nikon or Tokina or Tamron to make lenses for NON-Canon or non-Nikon SLR mounts...and that is why they do not make them.
The mirrorless camera lens mount cameras sell in numbers that do not justify entering the market, except for companies that actually manufacture mirroless cameras, so Panasonic, FujiFilm, Olympus pretty much "own" the market for lenses for the smaller-format mirroless lenses. Mirrorless models like the Oly and Fuji models get a lot of mind share on-line, and they are wonderful products, but the actual sales figures are dismal compared to ONE month's worth of Canon d-slr sales. In 2012 or 2013, the entire North America market of mirrorless cameras was like 30,000 units for the entire YEAR--maybe equivalent to say, like a week's worth of sales of Canon d-slrs. Olympus's camera division is close to being shut down...it is a money-loser. Panasonic's camera and lens biz is part of a HUGE corporation that underwrites a money-losing camera/lens segment. Not saying that their cameras or lenses are bad; far,far from it. It's just that they get a lot of mindshare on the web, but not a lot of broad, popular sales.
Not trying to be mean, but no, you really do not understand this industry.