I'm not sure why this is. Do they not consider submarines, for one reason or another, a strategic priority? Submarines have always been their weakness.
Even their strategic bomber may be put into production before a truly modern nuclear attack sub. Strange.
SSN/SSBN har been a weakness - not SSK subs. Remember, Chin has about 38 modern SSK subs. That has been focus for PLAN for the past 15 years. Of course, that foces i shifting more forward to SSN/SSBN subs as well.
You cannot go from coastal low-tech type 035 Ming-class SSK to a high-tech Yasen/Virginia-class in a few years, but China is catching up.
The point is PLAN needed to build a good, modern SSK force that can fight more regionally, and 38 modern SSKs (Improved Kilos, Songs, Yuans) are very good.
The U.S. has the largest SSN submarine force in the world, while China has the largest SSK submarine force in the world. So it's not like China is "without subs".
The U.S. doesn't have any SSKs, and those few Russia has are barely working, as they are older models, so Russia has just recently started to build Improved Kilos again - for their Black Sea Fleet.
Chinese surface fleet is superior&considerably stronger to that of Russia for example, or France or the UK, to mention a few countries. China doesn't have its forces spread thin either, like Russia and France - Russian fleet divided at four fleets whereas two of them are in the seas that can be blocked by NATO (Black Sea and Baltic Sea). Then you have Northern Fleet that is thousands and thousands of kilometers/miles from the Pacific Fleet.
Regarding bombers, it's on its way, and a stealth bomber will be introduced in a few years from now. Now the concentration is on J-20, J-31 and engines, regarding air power.
Also, interesting estimate by UK Ministry of Defence - China will spend as much as the U.S. on weapons (PPP) by 2045. I think it will be even earlier, as IISS projected. (Sometimes during 2030s).
Russia on the other hand, as you can see will experience a sharp, downwards trend, while India will take a clear, third place, but still waaaaay behind U.S. & China in spending.
List of countries by military expenditures - Wikipedia, the free encyclopedia