Missing basic CPS variables from IPUMS CPS

IPUMS CPS excludes a list of variables related to job, and I wonder why IPUMS CPS excludes these:

(see[WANTJOB], [BLVENOWK], [CANTFIND], [FAMDUTY], [ILHEALTH], [KIDDUTY], [LACKSCHL], [SCHLDUTY], [WRONGAGE], [OTHEREAS], [HANDICAP], [OTHEREAS], and [UNKREASN]).

I can only find these variables in ASEC, but it is a separate questionnaire. Can someone shed some light on the reasons for excluding these variables?

Sometimes variables are consolidated to better streamline the analysis for users. This seems to have been the case for the reason not looking for work variables you mention: WNLOOK aggregates these reasons and is available in the Basic Monthly Surveys. Other times, there are simply too many variables for IPUMS to harmonize all of them. In such cases, IPUMS will often provide an unharmonized version of the variable. In this case, UH_DWWANT_B1 provides the data available in WANTJOB for the BMS. I will see if the IPUMS CPS team would be able to provide a harmonized version of this variable, but for now you should be fine using this unharmonized variable.